Possible bug when dropping .png files onto signs

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create an empty forum
2. Drop a sign into it
3. Drop a .png file onto the sign
4. Boom

What is the expected output? What do you see instead?
Hoping to see a sign with a background image (whether or not this actually 
works isn't critical), but instead we get:

Unexpected Error
TSyncSendError: MessageNotUnderstood: UndefinedObject>>hasEqualElements:

OpenQwaq must quit.

What version of the product are you using? On what operating system?
CentOS 5.6 with - er - not sure how to tell the server version number. SVN 
snapshot taking in May 2011...

Please provide any additional information below.

Original issue reported on code.google.com by david.s....@gmail.com on 9 Aug 2011 at 2:05