According to some info about this problem I found, there is a few things that may go wrong.
First, the configuration of memory and so on the different WS can be a problem if you have an old version of Cakewalk or another editor program. The amount of data wanted/received from WS is not right, therefore WS may be confused about this and sends out a checksum error.
Secondly, the speed of the sent packages from computer to WS may problematic. In an infotext I found about this you was supposed to try different values for communication speed. Rather tricky to do, changing values in a Cakewalk *.ini file. I didn't notice any change.
Well maybe this is what is wrong, but I should try to get hold of another WS and another computer to test the software.
If you have a sysex program to look at the sysex code in itself you may spot what is wrong, but no kidding that is a hell of a job.
Ben Hall has written some interesting texts about the WS, try to search for the text on the web maybe he has something about your problem.
Good luck and I hope things gets better, says:
PEO!