IE7 hangs during import of customizations

This one gave me headache already a couple of times:
when you try to import customizations, the upload works fine but when you select "import customizations" or "import selected customizations" the following popup hangs. This is a known issue and seems to be connected with Internet Explorer 7. What I found was that the import has worked, it's just the visual feedback ("OK" button being enabled) that is missing.

there are 3 ways to resolve that:

1. install the hotfix (no download, needs to be requested from MS)
   https://mbs.microsoft.com/knowledgebase/KBDisplay.aspx?WTNTZSMNWUKNTMMYKORSXPPNNWUNVVRWPZPLMTWLPSRXUNXUTUUMMTPWXKUTYROM&wa=wsignin1.0
2. wait a few seconds, close the window and publish, the import has worked!
3. Use IE6
   

Note: This one is not fixed with the Rollup Update1.