If $ could be withdrawn from Fort Gox, then the price would go down sharply, maybe to the 50s.
But it seems that the cash out of Gox is still buying BTC and selling to other exchanges, which adds some
weirdness to the price formation. When funds leave Gox, the price - in Gox dollars - rises, instead of dropping.
The current supply / demand ratio points towards a price of 106, and there are almost 3k BTC to buy till 106.
It certainly is looking like what you describe. Many people are trapped on Gox, so to speak. That smaller percentage who may need cash have no choice but to sell elsewhere.
It is hard to believe how long this has been going on now. Further, the volume on Stamp has been rising and I have yet to hear problems getting money in or out. (Though there was a report from a few people about getting money in from Ing banking I think.)
It is further hard to believe that this problem could not have been corrected by now. As far as I've heard and seen, this should be an automated process.