If Mt. Gox had "serious problems with the US Government", there would be press releases from DOJ or the SEC, news coverage, and possibly arrests.
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://bitcointalk.org/index.php?topic=205694.0They have serious problems with CoinLab, which is suing them for good reasons.
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://bitcointalk.org/index.php?topic=148147.msg1579776#msg1579776They might have serious problems with some Tokyo banks. But even that is unlikely. If you have money, you can generally send it somewhere else. If you don't...
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.