Nema 23 cant go fast HELP ME!

Hello everyone!
I have a question about RPMs of stepper motors.

I have a kit from Longs motor: Nema 23 425oz motors, 350W 36V power supply and DM542A microstep driver
[www.longs-motor.com]

I can get only like 240rpms with my Nema 23 425oz, If i go faster (with Arduino), the motor just stops and produces strange noises (high pitch noises, but it doesnt move) and vibrations. What to do?All the thing is with no load on the motor shaft.,

Can u please help me what to do?

Best regards
Matic:(