System.Diagnostics.Process consistently wrong

I'm trying to get a handle to a process that is currently running. I've tried using System.Diagnostics.Process.GetProcesses(), but about a quarter of the processes returned are "System.InvalidOperationException: Process has exited..."

I can run the same exact code in a standalone non-Unity project and it will return all valid processes, but I can't seem to get it to work correctly within Unity. I've tried running Unity, Monodevelop, and a deployed build as Administrator with Compatability to Windows XP, but nothing seems to fix it.

Running:

Unity 4.0.0f7

Windows 7 Ultimate

Any help would be great, thanks.