Alexander,
Thanks for the help...I tried this out and it did help a lot, but it is still taking much longer with my dataset (for example, 80X80 cost matrix takes ~150 seconds to solve) vs the example ones. Any ideas--maybe normalizing of some sort?

Great code--I have found some interesting behavior. When I run the "standard" examples like A=rand(1000,1000) for the cost matrix, solves in seconds. However, I have an assignment problem (for PCB assignment) and when I run a 500X500 cost matrix it takes more than a day to solve. I have tried scaling the matrix values and also randomly shuffling the matrix elements and still doesn't reduce the solver time. Is there something inherent in the structure of the cost matrix that can cause the solution to take longer??