Wyse V30LE CE 1.2 Model VX0 Locks up frequently

Wyse V30LE CE 1.2 Model VX0 Locks up frequently

I have numerous Wyse terminals in the field that run really slow and lock up during operation. All the terminals are the same model and have the same image. I am wanting to know if anyone else has similar problems with thier terminals. Is there a known issue with terminals as they get older something happens with the flash memory that would cause the unit to lag and lock-up? Any help would be greatly appreciated. The servers seem to be running fine and no problem with load on that end.