When using the OptiLink with Laptop computers or computers with serial interfaces that have a low driving capacity, high baudrates often cause poorly functioning optical transmissions.
Set the baudrate in the Columbus software to 9600 Baud for Def-file transfers and to the best possible value (by testing) for card-actions?(Start with slow f.i 9600 to ensure good functioning, and test higher values if everything works fine).
You can set these values in DIRECT LINK|BAUDRATES.