Scheduled task fails with "Class not registered" error

[esher]

I can start up VBP 6.2a manually with no problem. When I start it from a scheduled task with the command line

"C:\Program Files\VisBuildPro6\VisBuildPro.exe" /b C:\nightlybuild\surfcam-svn.bld

it starts up the GUI, but also pops up a dialog box saying

Initialization of Visual Build Pro builder component failed: Class not registered

I can click ok on this box and manually make a build, but it makes the nightly build job hang. The weird thing is that this machine has been making builds successfully for over a month with no problem. This just started happening last Wednesday for no apparent reason. Uninstalling and reinstalling VBP had no effect, as well as getting the latest MS Windows XP updates.

Here's the information from Help->About. Any ideas?

Visual Build Professional 6.2a
Registered to: Surfware, Inc (1-computer license)
Windows Version: 5.1.2600.2.0
Install path: C:\Program Files\VisBuildPro6
SftTree_IX86_U_50.dll version 5.05
unins000.exe version 51.42.0.0
VisBuildCmd.exe version 6.2.1.1
VisBuildPro.exe version 6.2.1.1
VisBuildBld.dll version 6.2.1.1
VisBuildBurn.dll version 6.2.1.1
VisBuildCore.dll version 6.2.1.1
VisBuildDotNET.dll version 6.2.1.1
VisBuildExt.dll version 6.2.1.1
VisBuildLog.dll version 6.2.1.1
VisBuildMisc.dll version 6.2.1.2
VisBuildMS.dll version 6.2.1.1
VisBuildMS2.dll version 6.2.1.1
VisBuildNet.dll version 6.2.1.1
VisBuildSvr.dll version 6.2.1.1
VisBuildSvr.Interop.dll version 1.0.0.0