serial communication problem with i7 quadcore

I have three computers running XP SP3. Two of them have TBSilver installed.

The newer lab computer's MSI 865PE motherboard died (couldn't talk to SATA drives).

The computer was rebuilt wit a Asus P5G43T-m Pro socket 775 MB w/ DDR3 1333 GB FSB, etc. The processor is an Intel Q8400 Core 2 Quad 2.66 GHz.

I wrote and compiled an application that uses the serial ort to talk to a USB tto IEEE-488 converter. THe FTDI chip set and driver cause this device to appear as a serial port to the system. THe application worked fine on the computer when it had the MSI motherboard. It works fine on the oldest computer (10 years old)

With the new MB, the application hangs. The error message is the _com_open can't find the file (buffer #1).

When HyperTerm is run, it says the port is busy. Rebooting solves the problem (ugh!). HyperTerm can then talk to the USB to IEEE-488 converter.

Is there a timing problem with the serial communications library in that a faster computer gets to a needed place before the software does?