Copying and pasting text sometimes doesn't work with certain applications

When copying from wordpad, this appears (may not be relevant):

ixme:(..\..\dll\win32\ole32\stubmanager.c:629) No interface for iid {00000019-0000-0000-c000-000000000046}

Then when pasting into notepad, this appears and nothing is pasted:

(..\..\win32ss\user\ntuser\clipboard.c:939) err: Access denied!

err:(..\..\win32ss\user\user32\windows\clipboard.c:355) SetClipboardData(13, 00820044) failed

(The second arg for SetClipboardData is not always the same)

Same for copying from Firefox 3.6 (address bar and page content)

Copying from notepad to other applications works.