If you can only run your monitor at a crappy 60hz at 1024x786, it's time to get it exchanged! You should be able to run it at the recommended 1280x1024 @ 85hz with no problem. Sounds like you have a lemon. Call NEC customer support and I guarantee they'll send you a replacement for free (just don't wait until it's been 30 days since you made the purchase).

Don't settle for a faulty product!

Good luck.