[TYPO3] typo3v4 javascript error with filemounts

[Brian Bendtsen]

Hi

I have created my first site with TYPO3 version 4 and just created at 
new backend user. I have also created a few filemounts but when I press 
them I receive a javascript error. Have tried in both IE6.0 and Firefox. 
  Firefox says:

Fejl: document.getElementById("dragIconID_" + elementID) has no properties
Kildefil: 
http://mydomain/typo3/alt_file_navframe.php??currentSubScript=file_list.php
Linje: 343

and:

Fejl: dragIconCSS has no properties
Kildefil: 
http://mydomain/typo3/alt_file_navframe.php??currentSubScript=file_list.php
Linje: 314

Though I can still upload files. In Internet Explorer I cant.

Is this a known bug?

/Brian Bendtsen