Just looked into it - I can't reproduce what's happening. I looked at the first 3 pages of your inbox and didn't experience any issues, so I don't think it's a post.
When you load your inbox, are there any errors in the console of the browser? Should be under Developers Tools -> Console in Chrome, and someplace similar in firefox.
Weirdly, it works now. I haven't changed anything, perhaps there was a bug that was fixed in the dev version? Dunno, but it now works, thank you!
Strange, maybe there was a bug in a cached version or something... or gremlins!
Glad to hear it's working in this new version though. If it happens again we'll debug it a bit deeper and hopefully I'll be able to reproduce it.