Okay, Charles, I followed your instructions. The upgrade to 2.1 went perfectly and so moved on to the next steps you gave. I got this on the ubbaccel_test.cgi (nee php):
UBB Accelerator Test
Your PHP version is 4.06: OK
Your PHP version has zlib: Yes
Your PHP version will have no issues with the UBB Accelerator. The UBB Accelerator will use zlib compressed output.
I edited the ubb_lib.cgi as you instructed. Turned on the accelerator, but this is what I got as a message on the main board page:
Warning: Cannot add header information - headers already sent by (output started at /home/redboot/public_html/cgi-bin/ubb/ultimatebb.cgi:2) in /home/redboot/public_html/cgi-bin/ubb/ultimatebb.cgi on line 490
That's where I have a board set up for testing upgrades and such and I keep it closed except if the real board (same site host provider) goes down. However, the above error repeats itself from "line 490" to "line 494".
So, I took a wrong turn at Albuquerque somewhere. It's too bad, I have to tell you, Charles, that accelerator feature is Batmobile cool

Maybe if my site host ever goes with PHP 4.06 as its Apache module version, I'll have no problems.
It does show how versatile UBB is, though, since I almost got it to work even with my site host's round about approach to PHP 4. Thanks so much for trying to get it to work. I at least got some PHP experience our of it and that was very cool.
Zoom (atomic batteries to power ...)