This morning I logged in to Gmail as normal and clicked an unread mail. It opened and was completely blank. I tried another, same thing. So I tried some emails I had read yesterday, still blank. Panic!
A quick check on my phone and everything seemed fine. I then open Chrome and IE8 and logged into Gmail. Everything worked fine.
I checked with others in the office and no one was having this problem. It seems to be browser specific, related only to Firefox 7.0.1 and then only to certain accounts.
There’s a discussion on the Gmail Help Forum but it does look like Google have been playing around with their code a little. Maybe it’s related to the new look. Let’s just hope it’s fixed soon.
In the end this turned out to be AdBlock Plus that thought my email message was an advert and it was removing it. A little digging showed more specifically that the “Fanboy’s List (English)” filter subscription was the culprit. Disabling that and then reloading the page fixed the problem.