OP: Keep trying. The job market is still hot and there's plenty of good jobs out here.
My favorite thing to do while at UP was to work LinkedIn during conference calls when my Senior Manager (aka "director") would be shouting up and down because he hated life. It was during one such call that I got a message from a recruiter and landed great job. No constant on-call/working weekends/canceled vacation, more money, and a realistic personnel policy (i.e. one manager for twenty employees, not the other way around like it is at UP).
Hang in there. If I see a UP resume I'll make sure that they at least get a call back.
X-OMT