Personal Jurisdiction has a federal and state component. The federal component (due process) deals with things like whether you have mimimum contacts with the forum, whether the execercise of jurisdiction comports with traditional notions of fair play and substantial justice, and where you have purposefully availed yourself of the benefits and protections of the forum state. The State law component can usually be found in the State's "long arm" statute. Some states' interepret their long arm to extend to the full amount of jurisdiction allowed under federal due process, and some states limit their exercise of jurisdiction.
I would definitely speak with a lawyer. My thoughts are that if you lived in State A, signed a contract in State A to incur a debt secured by property in State A, and then defaulted on that obligation, State A is going to find sufficient minimum contacts. Remember, people on this board routinely sue out of state collection agencies in their own state based on communications directed at the forum state. Minimum contacts doesn't mean you have to live there.
Vanue is another issue, but that is usually decided by State procedural law (unless in Federal Court). Traditionally, State venue laws allow for the case to be filed in the venue where a contract was signed if the defendant resides in another State.
Again, I'd speak to an attorney in the state where you signed the contract to find out whether they can sue you there.
