FINALLY!
After tinkering with romance values, global variables and generally messing around with the inner workings of BG2 - a whole month's worth of trial-and-error work - I am now happily on my way to Suldanesselar with my original BG and original BG2 character, Tancred the Cavalier.
Why? You might ask. I've already completed the game with Tancred and co. Well, I'll tell you. For the first time, the rocky romance between Tanc and Jahiera has run its' course, with the two very much in love - after it seemed life, evil and several bugs had brought their relationship to a standstill. We go to fight Irenicus with added fervour now.
Why? Becuase this morning I downloaded Baldurdash's gamefix program! A mix of at least 50 bug fixes, this little package makes life so much simpler. Within the afternoon, the Romance was complete and the party were on their way. I strongly urge anyone who has not already done so to seek out and download this most awesome of unofficial patches at
http://members.home.net/mrkevvy/
Thank god, say I.
Tancred