Scanner Error Problem

Scanner :Umax Astra 5600
Windows: XP
Problem: While scaning popup error message :Try Again.
How to solve this problem?
i already reinstalled the drivers.but after 2 or three days the same problem i am facing.
if i restert the computer again the same arror is coming
we have about 34 UMAX Astra 5600 scanners installed in our office.and about 9-10 scanners are having the same error problem
Please help.

Regards
Ganesh