1. Uninstall any twain drivers you have in stalled for your scanner. RESTART
2. Install I/O driver "Port IO" from http://www.driverlinx.com/Software_Products/softwareproducts.htm .....RESTART
Port IO driver
3. In stall your twain driver http://www.maginnovision.com/Service_Support/drivers/dts3050.html
RESTART
Twain driver
PS Might work for othere parallel scanners..........