honestly, there are always some problems with crypts, but
i never lost anything !
This is pretty much the original set of exchanges that I signed upto,
spot the odd one out

mount gox : OMG!
btc-e : hacked
bitfinex: hacked
mintpal : Has he been charged yet ?
Bter : hacked
Cryptsy : No problems so far that we are aware
Same email ? Check your pc for keyloggers, do an antivirus scan, change your (email) password and don't use the same ids passwords on different sites.