I believe we've figured out what's going on. Some people's serial ports are unbuffered and the VISA driver is unable to keep up with the camera's processor which sends one byte immediately after the another. This can cause overflows and loss of data. This specifically applies to VISA error -1073807252 which indicates a hardware buffer overflow in the UART. I've added an option to the CMUCam2 LabVIEW Application allowing you to make the camera wait a certain number of bit periods between each byte that it sends. This will slow your transfers, but will eliminate the overflows.
Please let me know if you are unable to resolve the problem (specifically the error listed above) by increasing this delay. This isn't expected to solve any other errors.
Cheers!
-Joe