Sorry if I'm posting in the wrong section, but this was the only forum that was for problems. I don't get it, what's -1 messages?
My inbox is off sometimes too - It'll say I have a total of 25, and when I go back to it later, it'll say I have 4, but the inbox has 25
Another problem. I just checked my rep and I found that it's empty! I remember seeing a rep comment there a few weeks ago. It says I have 1 rep though. Also someone just -reped me and it didn't add up. Weird.
Someone stole your messages Lol, anywhose, it's just a forum bug, no big issue - it should dissapear once you get another pm.
It was probably 'caused by the downtime if you're wondering, forum bugs like these happen all the time, it's not like it'll eat up your mail ya know..
Another possible reason is if you recently delected a selection of PMs, then it will show up as -1. No one knows why but it has happened before quite a few times.