Yes I had it as well. It happened earlier in the day as well. I just closed it down and logged back on no problem. Bit scary isn't it with the sharp moves we've been having today!
Thanks Sid, at least I know it wasnt my system and like you I also just logged back on again. I know Skim uses different IB servers for some of her connections so I would be interested to know if she had the same issue.
Yes it did go down twice, but I just leave TWS it automatically logs back in. Well, mine does anyway, so perhaps it's an option I've selected at some stage hidden away in the depths of TWS.
IB does go offline occasionally, usually lasts 5 seconds or so, and often I don't notice until I get the Help suggestions screen up.
It's never bothered me actually, but then I can be quite relaxed about these things - I'm far more worried about getting runover by a bus!