Ar Tonelico 2 Cosmospheres and the end game glitch

So even though I swore off this devastatingly bad game quite awhile ago.... I couldn't help being a completionist and picked it back up.... well I am at the end of the game and I was aiming for Jaqui's Ending, not having selected to devote myself to either Luca or Cloche (Cannot move ahead in either one of their spheres....) and yet now I cannot move ahead in Jaqui's either!! I never even got a choice or was able to go to stonehenge in her fifth sphere..... I don't get it, even if I screwed up, shouldn't I at least be able to progress with one of the three girls???

Please tell me something just has not come to pass yet and all will be well with Jaqui...... Or have I managed to screw my chances with all the girls (not unlike real life...) through some error I was unaware I made?

Additionally I have one more question.... how prepared, or what strategies should I employ when I get to the "glitch" boss at the end? Any suggestions as to "must have/use" abilities items equipment et cetera, would be appreciated as I DID NOT come this far in this convoluted game to lose to a glitch now!!

Thanks for the help!

EDIT: Ok............ now I feel like a big fool....... I just figured it out... I had to re-enter and choose to accept Jaqui as my partner after going to "rest" somewhere.... I apologize for the false alarm..... But if anyone cares to take advantage of my erroneous post and talk cosmosphers, or more precisely just how freakin' annoying they are, lets have at it!!