#1) I think I need to be more clear by what I mean 'when a post doesn't show up". Oftentimes I will reply to a message (just as I am doing now) and then I hit submit. Sometimes all that does is refresh the page and I loose the brilliance (or insanity) of my post. It is probably not in the same line of troubleshooting you were going through.
As a workaround I am in the habit of doing a select all, ctrl C on all posts just so I don't loose my information.
#2) No this issue is sporadic, unpredictable. Javascript is always enabled, and *microsoft.com is always allowed. We do have a proxy between myself and the internet @work. The brand is the popular "Bluecoat" proxy.
Both issues occured on Windows XP (IE7), and Vista (IE7). It hasn't yet occured on my home PC running Win7
