A hanging Startup Script isn't too bad to troubleshoot. Using the Resultant Set of Policy (RSoP) too you should be able to get a list of the Startup Scripts applying to the computer. Since you only have a "couple" of Startup Scripts it's probably easiest if you look over the scripts individually and, if necessary, execute them as an Administrator (or as SYSTEM, if you'd prefer to completely simulate the startup process) to see which one is taking a long time to complete.
There's no good event logging, stock, that will show you which script is taking a long time to execute. I believe that verbose USERENV logging (search for the term "RunDiagnosticLoggingGlobal" to see what I'm talking about) would give you script execution start / stop events, but that's a lot of work to go thru if you only have a couple of scripts.
If I had a lot of scripts and no idea which one was slow I'd likely start w/ a binary search thru the scripts by denying the test computer rights to execute half of the scripts, then half-of-the-half, etc, until I located the problem script.
Fixing a broken script is probably beyond the mission of Server Fault, but this should let you isolate the slow script, at least.