I had the same error message come up a couple of days ago whilst saving a game of Championship Manager 03/04.
I posted in the SI Games forums and was advised that this was indeed a driver problem.
Do you have a Speed Touch USB Modem by any chance? Apparently the early drivers for this modem were known to cause this problem.
If so try the lastest drivers available from speedtouch.com. Version 2.01 I believe.
I uninstalled my modem and then re-installed it and the problem has gone away.
Hope that helps