Spybot SD 3 Beta 3 kills performance

Untill now I used Spybot SD 1.6.2 without Immunization, because as I realized, Immunisation caused a significant decrease of performance.

After installing Sybot SD Beta 3 on my PC (XP SP3, 1GB RAM, 3,4 GHz) I experienced a dramaticly reduced Performance even without Immunization. So it takes much more time to open a first explorer window (at least 2 to 3 times longer). In the explorer window then, when I rightclick a file or directory to open the contextmenu for the first time, it takes up to 5 seconds (normaly it should take much less than a second. To open the context menu of an object again takes less time but is still much slower as it should be and as it does without SP installed.

Another effect is, that it is no longer possible to open Word- and Excel (Office 2003) documents by double clicking or using the documents context menu entries 'open' or 'open with'. The acording programs are still started but no documents are opend.

Now after uninstalling SP SD 2 the system works again well and fast as before.