no file selector with IE6

Filevista works fine with ie8, opera and firefox here. Now a customer wants to upload files with IE6. After pressing the upload button nothing happens. I have tried all tree methods (basic, ajax and flash) but nothing works. What is the problem with IE6 ?

I tested the demo version at gleamtech.com. It works fine. So this seems to be a problem with our installation or Server setup. What do I need to check/change to fix this ?

Note that after the intial v4.1 release, we released some fixes.
Please apply the latest fix (it includes all previous fixes) to your installation:
Fix 3 for FileVista v4.1

We always update the live demo with the latest fixes that's why you may have not experienced the same error at that time.