This problem can be a bit persistent. But if you uninstall Eraser 6 (and remove any part of Eraser 5 if you still have bits of that left on your machine), remove the Task list and Registry keys manually, then run a registry cleaner (such as the one in the free CCcleaner), the problem always clears, or at least it does for me, when you reinstall Eraser 6.0.7, which is the current 'stable' version, and the one you should use.
I have an XP PRO SP3. I have tried doing all that has been suggested and it includes: (1) cleaning out registry keys, (2) cleaning out all the Local Settings file, (3) deleting the Program Files folder, (4) rebooting. All to no avail. Eraser 6.0.6 loads and works just fine.