Donna's SecurityFlash reports users who are using Spybot S&D's immunization may experience slow downs or system hangs with Microsoft's new Internet Explorer 8 browser. The problem also occurs with IE-SPYAD and SpywareBlaster, it's related to the long list of restricted sites that these security tools add to Internet Explorer.
There is report of high-CPU usage when Spybot –S&D immunization is enabled. I able to reproduce this in XP.
There is also report that IE8 will not load fast or it will hang if restricted sites exists in IE Restricted Sites zone, e.g. using IE-SPYAD and I able to reproduce this also in XP and Vista.
Time for the authors to check their protection tools for IE8 compatibility. For now, users who want IE8… should disable the immunization and IE-SPYAD. For users who prefer the protection over IE8, stay first with IE7.