RH8 hangs with 100% CPU when closing a topic. Resource Manager to blame?

Please refer to the following thread for background information: http://forums.adobe.com/thread/734972?tstart=0

I'm re-listing this issue, as it has rasied its ugly head again, and I've no resolution this time.

Summary:

The original issue was that RH8 would hang whenever I closed a topic for anywhere between 15-30 seconds before allowing me to interact with the application again. Attempting to interact with the GUI during this freeze would result in the 'Not Responding' message at the upper-left of the application window (suffice it to say I'm on a PC with Windows).

After much investigation it was suggested to me that my profile may be corrupt, and in order to test this, another user should log on and see whether they experienced the same problem. As it is, they did not. So I had my Systems Admin recreate my domain profile, and everything worked just fine.

...until now.

Last week we all upgraded from Windows XP to Windows 7 (32 bit). We also changed our anti-virus software. The awful hanging issue in RH has returned.

We've attempted the solution from last time, by recreating my profile on the domain, to no avail. We have in fact gone to the extent of reformatting the hard drive and reinstalling Windows, the anti-virus software and RH8 (plus all available patches) from scratch. In case anyone is wondering, we've tried running RH without the antivirus installed, and when installed have also tried excluding the RH application folder and all my project folders, just in case it was the anti-virus software at fault. Regardless, the RH problem exists.

I can't understand why I'm now having this problem. Truth be told, I never really understood why recreating my domain profile in the first place resolved the problem last time.

However, I have now discovered something else...

In my RH Resource Manager I have a few thousand images in the Image folder. Not much I can do about this - the applications I write Help for have many screens users can access, and I write the Help for half a dozen applications. When I delete the contents of the images folder within the Resources Manager, RH works perfectly - no hanging whatsoever. As soon as I import the images into this folder again, the hanging is back. I have tested this a few times now, and have rebooted and had another user log on to confirm, and it happens every time. I'm dumbfounded of course, particularly because the same set of images has been sitting in the Resource Manager for months (since my original post about this issue, last year), and RH has been working perfectly.

I've also tried Peter Grainge's suggestion to create an empty BaseCSS_res.dll file (http://www.grainge.org/pages/authoring/rh8/using_rh8.htm), but as I've installed all the RH8 updates, this shouldn't be an issue.

I've also tried deleting the CPD file without success.

Thanks in advance.