^Bump
Hi there; similar problem for me.
I'm at the same stage in the main quest line - I have to convince Tullius and Ulfric to sit down together and have a chat with the Greybeards. I can convince Ulfric fine, but with Tullius my dialogue is limited to either "take the oath to join the imperials", or "think it over a little more" (paraphrased).
Obviously I've done the first stage in joinging the imperials (cleared out a fort) and reported back to the Nord General (or is it Legate?) standing opposite Tullius, but I don't want to take it any further and join the Imperials. Surely Tullius has other things to talk about than me joining the Imperial ranks.... I would think that when I click "think it over", it should return me to a broader set of topics to discuss with him, including getting him to the meeting with Ulfric and the Greybeards... instead it just exits dialogue with him.
Please fix this ASAP - I want to continue the main story!
On a lighter note, kudos Bethesda - put simply, it's an outstanding game. I expected something superb to continue The Elder Scrolls, and boy did you guys deliver!
Peace.
y
*** edit ***
Damn - after posting I realised I'm on the PS3 section - I'm PC.... (I searched this problem and this post came up).