Anyone else has any similar experience?
The present situation is clearly exceptional, however when Mt.Gox was working reliably (well, sort of...), it was standard practice for them to not show in the account balance money that you requested to withdraw and was stuck in the withdrawal queue. If you had $1000, had requested to withdraw $500 and they were still processing it, your balance would only have shown $500.
So, yes, having a zero balance would have been pretty standard Mt.Gox behaviour if you had requested to withdraw all your money.
Of course, this doesn't actually mean anything under the present circumstances (money supposedly stolen, bankruptcy filing, etc.); just saying that the web site is acting exactly like it did before.