Shader Error - Exception during Compilation

After upgrading to Unity 3.5.5f3 our build server now seems unable to compile any shaders. We are getting lots of errors like these:

Shader error in 'Unlit/Masked Colored': Program 'frag', *** exception during compilation *** at line 751
Shader error in 'Unlit/Masked Colored': Program 'vert', *** exception during compilation *** at line 751

It works ok on dev machines and the shaders have not changed, so I assume the error must be in the compilation process. The build server is a dedicated Windows Server 2008 R2 Enterprise machine. (Meaning: it does not have a fancy graphics cards and maybe not the latest DirectX-Version. But it worked ok for months now… it stopped after the Unity upgrade, at least that is what I believe.)

Is anyone seeing the same problem?

Ok, solved it. Just in case anyone cares: you have to disable Data Execution Prevention for user processes. The shader compiler will crash otherwise.