what is your Wireshark version?
Can you post a sample capture file on cloudshark.org?
HINT: As you cannot delete an anonymously uploaded file on cloudshark.org, you better don't post any private data. Post just those packets in a capture file, that are required to analyze the problem.
UPDATE: looks like this bug: https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5958
answered 16 Jul '12, 03:34