Having the same problem.
Did anyone found a resolution for this yet?
Tnx,
Bert
I have been having this problem for the last four months and I finally got it resolved...
The problem is the line that looks like this when viewing the source is not loading properly:
<script src="/components/com_virtuemart/fetchscript.php?gzip=0&subdir[0]=/themes/italomty&file[0]=theme.js&subdir[1]=/js&file[1]=sleight.js&subdir[2]=/js/mootools&file[2]=mootools-release-1.11.js&subdir[3]=/js/mootools&file[3]=mooPrompt.js&subdir[4]=/js/slimbox/js&file[4]=slimbox.js" type="text/javascript"></script>
I added the following lines to my template header and it solved my problem:
<script type="text/javascript" src="/includes/js/joomla.javascript.js"></script>
<script type="text/javascript" src="/media/system/js/mootools.js"></script>
<script type="text/javascript" src="/components/com_virtuemart/js/mootools/mooPrompt.js"></script>
<script type="text/javascript" src="/components/com_virtuemart/js/slimbox/js/slimbox.js"></script>