I would consider the seizure of a Credit Union account by the US Department of Homeland Security to be serious problems with the US Government https://bitcointalksearch.org/topic/mtgoxs-dwolla-account-in-the-usa-has-been-seized-by-the-dhs-205694
I would rather not comment on the merits or lack thereof of a lawsuit before the courts. I will point out a thread back in March where I asked a series of mundane questions regarding compliance in Canada I received a prompt response from MTGox but no response to this day from Coinlab so I will let the reader be the judge here. https://bitcointalksearch.org/topic/m.1579776
Mt. Gox had trouble at the US end, they'd probably be blocked from receiving money transfers. They're not. Somehow, the only things that don't work are things that take money away from Mt. Gox. That's very convenient for Mt. Gox.
I still believe the problems are regulatory and not financial.