@Ron:
You almost certainly have problems on those quad installations if that is all they can do on 2665.
I am currently running a 2665 on my Q6600[
oc to 3.4G], it's at 60%. 2324 ppd, 12 minutes 15 secs per step. Even if you aren't overclocked, it shouldn't be that slow.
Windows reports 25% per core, and that is normal. Do this: check task manager. Do you show 4 fahcore_a1.exe processes? Are they at 25% under load? I run the DEINO version, and have found it to be more stable than the MPI version. There are 4 core processes, 5 deino processes, and 1 for mpiexec.
Are you running GPU clients on those machines as well? Try running the SMP client alone, and see if the result is the same.
Personally, I would rip the whole install out completely, and reinstall again, including a repair or reinstall of .net 2.0 under the admin credentials. Then see what happens.
Follow the install guide here carefully:
Folding@home - Guide
BTW, what OS is that? Everything I have said here is based on XP. Vista has different quirks; the install guides will show you.