Using Thunar 1.2.1 on Solaris x86. If I right-click on a file in Thunar and select delete, then Thunar does delete it (moves it to the trash). However, the file is still shown in Thunar. So you can still try and act on it, but of course you just get errors because the file isn't there any more. What should happen is that the file is no longer shown.
I can reproduce this only with locations that do not support file monitoring. For those there is an easy fix, I suppose. I'll look into it.
I'm marking this as a duplicate of another issue that is about solving the problems we have with lack of file monitoring on some locations. *** This bug has been marked as a duplicate of bug 6409 ***