Hmm this is an intriguing one, have you tried uninstalling IE9 and seeing if the same problem occurs with IE8
I can see no apparent malware and the main registry associations look good
I would like you to run the following programme, it would be best doing it overnight as it will take a while. But it will rule out a malware cause
Download Dr Web from here
http://www.freedrweb.com/?lng=en link on the top right of the page, tick the EULA and then download
It will download as an 8 digit file save it to your desktop
Restart in safe mode and run
Accept the enhanced version
Then run the quick scan
About halfway through you will be prompted to buy - just X the box closed
Once finished it will generate a log please attach that