Failure due to log being truncated

[smeadows]

Okay a little more information,

We are running it on a dual processor machine.
Does VBP even support devenv.exe on dual processors?

Another thing we noticed is that we have the option
"Parse build output for failed projects"
turned on, in the help it says this:
Parse build output for failed projects: Sometimes, devenv.com will return a success (0) exit code even if one or more projects failed to build. If this box is checked, the action also parses the build output to verify that 0 projects failed to build, and if an error condition is found, the step will also be marked as failed. This flag does not apply when building Visual Studio 2005 projects with msbuild.exe.

In what cases will it return 0 on a failure?
Has this been documented anywhere by microsoft, cause I can't find any more info on it?
Would this in fact try to parse the log before the spooler finsihed dumping it?

thx for your help