Lone : Microsoft had to revoke it's release of it's Virtual Machine Runtime. They had this included in the first release of SP1 (Sp1a) ... Later they revised it in the Sp1b.
Applications like norton Av use scripting which invokes the virtual machine. In the absense of which these error occur.
Also if you still are unsure about this ..then read a little more on the msjava using google or microsoft's website.
Sasoon : Did you try what i said ??