What happens if you:
1. click "Open a previously captured file"
in the middle pane of the Welcome screen ?
2. Hit cancel on the "File Open" window which pops up
3. Try to a different button on the Welcome screen.
Yep... Wireshark attempts to open a capture.
OK: Please add a comment to Bug #2478 with the version output from
Wireshark -v (and mention that the problem also happens when clicking
the "How to Capture" and etc.
Thanks
PS: I recently looked at this again but found nothing obvious
(on XP).