McAfee 4.5 disabling w/Internet Explorer

We have McAfee 4.5 installed on workstations and regularly update virus definitions. Over the past several weeks (after the last few updates) when Internet Explorer is used, McAfee AV is disabling itself.

The systen scan can be enabled, but will disable again when IE (5, 5.5 or 6.0) is used.

Has anyone seen this and/or have a fix for the problem?

Thanks.