The eraser and drawing tools on Elements 3.0 have locked up. I can't edit with these tools at all. This has happened before and mysteriously resolved itself (with 2.0 as well). I have reset the tools and rebuilt the preferences, they still don't work. I have played with new layers to make sure there is no problem with layer locking, etc. The tools worked fine two days ago. Any ideas?

Thanks in advance,

Darwin