BankRate.com has Q&A related to trouble refinancing because the bank says that they are upside-down on the mortgage (mortgage is higher than house is worth). The key take-away from the article is to make sure you know how your ARM works when it resets. The Fed has already dropped the fed funds rate 300 basis points and many short-term rates have followed that path. As such, there is a chance that your reset may be a lot lower than you think. Bankrate also has various calculators (or here) to help you find out if it makes sense to refinance.