Bullguard Internet Security on VIsta

If you are running Windows Vista and have Bullguard AV installed read on.
We have been wrestling for some time with a computer that intermittently runs slowly, but then recovers. This has now been on the bench for 3 days.
Bullguard has integrated anti-spyware so we turned off Windows Defender - it works better however...
We thought we ought to run a virus scan. Ran the Bullguard scan and after 1.5 hours with only 7% complete we cancelled this. We ran Panda Active Scan which identified in about 1 hour 20 minutes that there were 11 infected files, so back to Bullguard and let it run.
After 2 hours still on 7% complete, 800,000 files out of 1400000 files scanned and the number of files to scan increasing faster than those scanned and 23 hours left to run to completion.
We sent an email to Bullguard and got the following response "Because the system is running Windows Vista, please make sure that the following Windows features are currently Disabled: Windows Defender, Windows Firewall, User Account Control. Know that these modules can lead to conflicts with the BullGuard plug-ins and also slowdown of the computer."
This is not good news, but our main gripe is to underestand why Mesh who supplied this machine shipped it with full featured Vista when the AV product is known to have these issues.
Our policy would be to ship an AV product that does not cause these conflicts or turn off those features that cause the conflict.
Of course many people turn off Vista UAC but is that really the right thing to do?

New malware threat hits unprotected computers

Today we have had two incidents of a pernicious malware infection which is identified by the desktop background being altered to a red image with a 'Privacy protection threat' warning. It is accompanied by a number of popups trying to get you to obtain malware removal programs. These popups appear at regular intervals even in idle mode. Both machines also had the Windows Task Manager disabled although regedit and msconfig were available for use.
These two incidents are on unrelated equipment. One machine had a copy of McAfee installed but we cannot vouch for the state of the updates licence. The other machine had lost it's antivirus and was thus totally unprotected. We believe the infection has been brought in by a trojan horse but our invesigations have not identified the causal agent.
The totally unprotected machine allowed us to install and run Panda AntiVirus, which removed some threats but did not entirely clean the machine. We did a system restore to a week ago and then reinstalled Panda. Other machines on this network which were protected seem to be unaffected.
The other machine gave us grief. We could not get Panda installed initially because we could not remove McAfee. We disabled startup options in msconfig and trawled through registry to remove relevant McAfee keys. We have loaded Panda and done a system scan but we are not sure how complete the clean up has been. We may have to use system restore on this one as well.
This malware seems to strike fast. Dont let it cripple your system. keep your anti virus up to date.
Both systems running WIndows XP. One using XP Home, one XP Professional. Both SP2.