diff --git a/plugins/kolab_files/kolab_files.js b/plugins/kolab_files/kolab_files.js
index 4e81c0fa..3b8a58e8 100644
--- a/plugins/kolab_files/kolab_files.js
+++ b/plugins/kolab_files/kolab_files.js
@@ -401,10 +401,10 @@ function kolab_files_upload_input(button)
   // Note: now, I observe problem with cursor style on FF < 4 only
   // Need position: relative (Bug #2615)
   link.css({overflow: 'hidden', cursor: 'pointer', position: 'relative'})
-    .mouseenter(function() { this.__isactive = true; })
+    .mouseenter(function() { this.__active = true; })
     // place button under the cursor
     .mousemove(function(e) {
-      if (rcmail.commands['files-upload'] && this.__isactive)
+      if (rcmail.commands['files-upload'] && this.__active)
         move_file_input(e);
       // move the input away if button is disabled
       else
@@ -412,17 +412,16 @@ function kolab_files_upload_input(button)
     })
     .mouseleave(function() {
       file.css({top: '-10000px', left: '-10000px'});
-      this.__isactive = false;
+      this.__active = false;
     })
     .attr('onclick', '') // remove default button action
     .click(function(e) {
       // forward click if mouse-enter event was missed
-      if (this.__isactive)
-        return;
-
-      this.__isactive = true;
-      move_file_input(e);
-      file.trigger(e);
+      if (rcmail.commands['files-upload'] && !this.__active) {
+        this.__active = true;
+        move_file_input(e);
+        file.trigger(e);
+      }
     })
     .mouseleave() // initially disable/hide input
     .append(file);