EDIT: As a last resort I created a new user account on the mac,
reinstalled LOTRO. And it works. Finally. So it was a software
clash somewhere that had also managed to affect the last new user
account I made. I still don't know which app or service is
interfering with LOTRO but at least here is a fix that seems to
work.
EDIT2: Spoke too soon! Ran once and now I'm back to square one. It's
a bit of a chore to re-download each time I want to play. Maybe its
time to look on ebay for a second hand PC, or drop LOTRO *sigh
This is beginning to sound like you have Mac OS issues. And the fix is not easy or pretty.
Some time ago I had an iMac and a MacBookPro ... both were running the same version of Snow leopard. The iMac had no problems of any sort with CXG or LOTRO. The MacBook Pro, however, had a constant stream of weird problems. The basic difference between the two systems? The iMac had been a virgin install of Snow Leopard, but the MacBook Pro had been upgraded from Tiger.
Finally, after about 3 months of serious debugging I finally bit the bullet, wiped the MacBookPro and did a virgin install of Snow Leopard (no upgrade of any kind.) It hasn't had a problem since then.
So, my analysis -- The MacBook Pro had been in use for several years under Tiger before being upgraded to Snow Leopard, and was heavily use by my son for an assortment of Audio and Video "things." The iMac had never had any of those "things" installed on it. It was well known that there was much software that ran under Tiger which would not run under Snow Leopard. By doing the wipe and virgin install, all of the "cruft" from years of installing and "uninstalling" software, especially software not written expressly for the Mac, was removed. AND... all of the assorted "conflicts" that didn't effect most things but did effect WINE.
So, my only suggestion at this point is to wipe your HD, re-install OSX from DVD and start over.
As I said, neither easy nor pretty.