First, if I may, address macnerd's addition: for whatever reason, I can't boot into SUM, so AppleJack won't even initialize...it won't go beyond the gray screen till I release cmd-s and allow it to boot fully...then it boots 'normally'.
Now, as to the programs:
I took the proffered advice and disabled Sophos; it was pretty highly recommended, so I figured it wouldn't hurt, y'know?
As to doing the Boot Disk repair, I followed it (literally) "by the book" with a printout of the instructions from Apple and my OSX disk, and to my knowledge followed the instructions to the letter in 'repairing permissions'. That said, I'd also read that OnyX has been sending out a 'disk needs repair' message in error for some time now, which apparently is a bug to be worked out and not an actual disc issue. I figured this out because I'd 'repaired' the disk and permissions several times in fairly close procession, and had the same message come up at the same point...and the SMART status was always OK. I dunno.
As to the SMC program, I've tried to keep the fan speeds in close harmony so as not to disrupt the cooling flow, as I know the 1st-gen MPs like mine get hotter than the newer ones (at least the RAM does). Before I installed the program, the RAM was running in a range from the low 90's to around 140 or so (F). Now, since the RAM isn't all sitting in a nice row directly in the airflow, I'm assuming that the memory closest to the airflow is coolest, right? After installing the SMC, temps began running in the realm of 78-91F, and it seemed the computer became much crisper & quicker in operation.
I could be reading into it here, but from what I've experienced, I like what the SMC does, and disconnecting it doesn't seem to produce anything other than higher temps, at lease vis-a-vis hanging or SBBOD's.
I do agree with you on the IPSec though...I would think that any software program that acts as a firewall would slow things down. Guess I should shut it off and see what happens there.
You guys are great; thanks for your help, and I'm keeping my eye on this thread for any other ideas/suggestions that might help!!!