ClassicBoard driver problem? Written message seems to be cut?

Hello,

we have a problem with writing to serial ports with ‘WriteFile’ function. The last 6 characters of the message seems to be cut, but the function returns, as if everything worked well? This problem occurres since Update from OS WindowsNT to Windows2000. We use the new Window2000 driver and tested it with different configurations. We have configured the FIFO-options to high-level know, but this does not solve the problem.

When we add 6 additional Spaces to the message and call WriteFile (with length, increased by 6), everything seems to work well: The message is send exactly without this 6 Bytes.

Do You know about this strange behaviour or have an explanation or a more elegant solution for this ?