diff --git a/content/student/studentenoverlay.xul.php b/content/student/studentenoverlay.xul.php
index e56fa344c..28eeaf889 100644
--- a/content/student/studentenoverlay.xul.php
+++ b/content/student/studentenoverlay.xul.php
@@ -58,7 +58,7 @@ else
 			<!-- *************** -->
 			<!-- *  Studenten  * -->
 			<!-- *************** -->
-			<vbox id="studentenEditor" persist="height">
+			<vbox id="studentenEditor">
 			<popupset>
 				<menupopup id="student-tree-popup" onpopupshown="">
 					<menuitem label="Student aus dieser Gruppe entfernen" oncommand="StudentGruppeDel();" id="student-tree-popup-gruppedel" hidden="false"/>
@@ -129,12 +129,14 @@ else
 				<!-- ************* -->
 				<!-- *  Auswahl  * -->
 				<!-- ************* -->
+				<vbox flex="1">
+				<vbox>
 				<tree id="student-tree" seltype="multi" hidecolumnpicker="false" flex="1"
 						datasources="rdf:null" ref="http://www.technikum-wien.at/student/alle"
 						<?php echo ($xulapp!='tempus'?'onselect="StudentAuswahl();"':'') ?>						
 						flags="dont-build-content"
 						enableColumnDrag="true"
-						style="margin:0px;"
+						style="margin:0px; height:150px"
 						persist="hidden, height"
 						ondraggesture="nsDragAndDrop.startDrag(event,studentDDObserver);"
 						context="student-tree-popup"
@@ -300,7 +302,7 @@ else
 	      				</rule>
   					</template>
 				</tree>
-
+				</vbox>
 				<?php
 				if($xulapp!='tempus')
 				{
@@ -352,4 +354,5 @@ else
 				}
 				?>
 			</vbox>
+			</vbox>
 </overlay>
diff --git a/include/rdf.class.php b/include/rdf.class.php
index 46fc6b9dc..23c77812b 100755
--- a/include/rdf.class.php
+++ b/include/rdf.class.php
@@ -106,6 +106,8 @@ class rdf
 	 */
 	public function setAttribut($name,$value,$cdata=true)
 	{
+		if(!isset($this->attr[$this->counter]))
+			$this->attr[$this->counter] = new stdClass();
 		$this->attr[$this->counter]->name=$name;
 		$this->attr[$this->counter]->value=$value;
 		$this->attr[$this->counter]->cdata=$cdata;
diff --git a/include/student.class.php b/include/student.class.php
index 8fec7fa63..5e3864f02 100644
--- a/include/student.class.php
+++ b/include/student.class.php
@@ -340,16 +340,19 @@ class student extends benutzer
      */
     public function getStudentsStudiengang($studiengang_kz, $semester = null)
     {
+	/*
         if($studiengang_kz == '')
         {
             $this->errormsg ="Es wurde kein Studiengang übergeben";
             return false; 
         }
-    
+    */
         $qry = "SELECT * FROM public.tbl_student 
             JOIN public.tbl_benutzer ON (student_uid = uid)
             JOIN public.tbl_person USING (person_id)
-            WHERE tbl_benutzer.aktiv = 'true' AND studiengang_kz =".$this->db_add_param($studiengang_kz,FHC_INTEGER); 
+            WHERE tbl_benutzer.aktiv = 'true'";
+		if($studiengang_kz!='')
+			$qry.=" AND studiengang_kz =".$this->db_add_param($studiengang_kz,FHC_INTEGER); 
         
         if($semester != null)
             $qry .= " AND semester =".$this->db_add_param($semester, FHC_INTEGER);
@@ -741,4 +744,4 @@ class student extends benutzer
         }
     }
 }
-?>
\ No newline at end of file
+?>
diff --git a/include/wochenplan.class.php b/include/wochenplan.class.php
index 1ea108009..af1a2bbee 100644
--- a/include/wochenplan.class.php
+++ b/include/wochenplan.class.php
@@ -123,6 +123,8 @@ class wochenplan extends basis_db
 		for ($i=1; $i<=TAGE_PRO_WOCHE; $i++)
 			for ($j=0; $j<20; $j++)
 			{
+				if(!isset($this->std_plan[$i][$j][0]))
+					$this->std_plan[$i][$j][0]=new stdClass();
 				$this->std_plan[$i][$j][0]->anz=0;
 				$this->std_plan[$i][$j][0]->unr=0;
 			}
@@ -291,12 +293,16 @@ class wochenplan extends basis_db
 		{
 			if($row = $this->db_fetch_object())
 			{
+				if(!isset($this->studiensemester_now))
+					$this->studiensemester_now = new stdClass();
 				$this->studiensemester_now->name=$row->studiensemester_kurzbz;
 				$this->studiensemester_now->start=mktime(0,0,0,mb_substr($row->start,5,2),mb_substr($row->start,8,2),mb_substr($row->start,0,4));
 				$this->studiensemester_now->ende=mktime(0,0,0,mb_substr($row->ende,5,2),mb_substr($row->ende,8,2),mb_substr($row->ende,0,4));#
 			}
 			if($row = $this->db_fetch_object())
 			{
+				if(!isset($this->studiensemester_next))
+					$this->studiensemester_next = new stdClass();
 				$this->studiensemester_next->name=$row->studiensemester_kurzbz;
 				$this->studiensemester_next->start=mktime(0,0,0,mb_substr($row->start,5,2),mb_substr($row->start,8,2),mb_substr($row->start,0,4));
 				$this->studiensemester_next->ende=mktime(0,0,0,mb_substr($row->ende,5,2),mb_substr($row->ende,8,2),mb_substr($row->ende,0,4));
@@ -358,6 +364,8 @@ class wochenplan extends basis_db
 			while (isset($this->std_plan[$tag][$stunde][$idx]->lektor_uid))
 				$idx++;
 			//echo $idx.'<BR>';
+			if(!isset($this->std_plan[$tag][$stunde][$idx]))
+				$this->std_plan[$tag][$stunde][$idx]=new stdClass();
 			$this->std_plan[$tag][$stunde][$idx]->unr=$this->wochenplan->lehrstunden[$i]->unr;
 			$this->std_plan[$tag][$stunde][$idx]->reservierung=$this->wochenplan->lehrstunden[$i]->reservierung;
 			if ($this->wochenplan->lehrstunden[$idx]->reservierung)
@@ -1221,8 +1229,8 @@ class wochenplan extends basis_db
 						// Ausgabe
 						echo '<button id="buttonSTPL'.$count.'"
 							tooltiptext="('.$updatevonam.') '.$titel.' - '.$anmerkung.'"
-							style="border:1px solid transparent;'.((isset($farbe) && $farbe!='')?'background-color:#'.$farbe:'').';"
-							styleOrig="border:1px solid transparent;'.((isset($farbe) && $farbe!='')?'background-color:#'.$farbe:'').';" ';
+							style="border:1px solid transparent;'.((isset($farbe) && $farbe!='')?'background-color:#'.$farbe:'').';-moz-appearance:none"
+							styleOrig="border:1px solid transparent;'.((isset($farbe) && $farbe!='')?'background-color:#'.$farbe:'').';-moz-appearance:none" ';
 						if ($berechtigung->isBerechtigt('lehre/lvplan',$stg_obj->oe_kurzbz,'uid'))
 							echo ' context="stplPopupMenue" ';
 						if ($berechtigung->isBerechtigt('lehre/lvplan',$stg_obj->oe_kurzbz,'u'))