New ST-i shutter working backwards

I attempted to use my new ST-i CCD camera tonight for the first time with my 80mm guide scope. I had installed the latest drivers, and SBIGDriverChecker64 reported that all my drivers are up-to-date. The camera firmware version is 2.37.

The shutter appears to be working backwards. Using CCDOps, and taking a Grab with dark frame set to "None" (to take a "light exposure"), the shutter closes. Taking a Grab with dark frame set to "Only" (to take a "dark exposure"), the shutter opens. Also, when I enter "Focus" mode, the shutter closes, which makes it impossible to focus the camera.

This appears to be the same issue that Nik Joshi reported here last month: http://www.diffractionlimited.com/forum/index.php?threads/st-i-shutter-working-backwards.1998/.

I'd appreciate any help or advice from SBIG on this issue. Thanks.