My ignorance regarding the nature of the OSX/X11 integration has been cured, thanks to comments below, and if you are looking for tips regarding copy-and-paste in X11 under OS X, read on. Regardless, I'm still irked that Apple Care couldn't so much as point me in the right direction. I leave this posting here in the hopes that it helps someone else who had the same issues.
I know I'm going to buy the Apple Care support package. After all the problems I had with my Sony during its third year I would have to be nuts not to buy a three year support package on my shiny new PowerBook. But, damn it, I won't be buying it today! I'm too irked at Apple's support policies. They apparently only marginally support some of the applications that come on the 10.4 (Tiger) install DVD, and of course that would be the application currently giving me a headache...
My PowerBook came with OS X 10.4 pre-installed. Basic install, none of the optional packages. During the course of installing all my favorite applications I found that Visual SlickEdit requires X11 be installed. (I would not be having this problem if they wrote a native OS X implementation; but given OS X supposed flexibility, porting one of their unix versions to use X11 on OS X seems reasonable. Seems...)
I installed X11 off of 10.4 disk 1. It launches. An xterm window opens. As far as Apple is concerned, their support stops here. It matters not to them that copy-and-paste doesn't work. I can select text in this xterm window, go to Edit/Copy and when I go back to Edit the Paste option is greyed out. Nothing made it to the buffer when I did my Copy. Apple doesn't support X11 beyond launch because they don't want to support third party X11 applications. Completely reasonable, except my problem exhibits itself in the xterm application that came with X11 that came with Tiger on a DVD with the Apple logo. That didn't sway the position of the Apple Care support person, Elliot, with whom I spoke. It launches, so he is off the hook as far as supplying a useful hint or suggestion or, gods forbid, a solution. Elliot did offer to email me a URL to a support page regarding X11. I gave him my email address but the email never arrived.
I'll buy Apple Care later, because Apple doesn't Care today.
ps. Please DO NOT reply to this posting on the LJ feed account (tampagypsy_feed). Follow the links back to my webite and reply there if you feel the need. There is no way to easily integrate comments from the LJ site back into my own weblog, so the effort of posting to the LJ site is wasted as I will never read itâ€¦