Is there some reason i can't level up in ACT 2? I've just completed several quests and my xp is at 26012/26000 with my xp bar full up yet I'm unable to reach level 27, is this a bug or some sort-of level cap for Act 2?

On higher difficulties (hard and up), leveling up requires meditating. Do you see the plus sign indicating a new level on screen? If not, it could be that the xp indicator is flawed and that you'll get the level after gaining some more xp.

it does sound like a bug, i did have a point in chapter 2 where i no longer got xp from enemys and only leveled up after finishing quests but never got stuck with a full bar. try compleating another quest and if nothing happens then reload to a point before you hit level 27. the having to meditating is only for distrbution of points not actually leveling up.

Nope, no plus and in the character screen there are no talents to spend, yes the xp bar is completely full.

I'd try this. Maybe the 'internal' amount of required XP differs from what is shown in the UI, due to a bug.
Get some more XP and report in. :)

Thanks for the info, to the others i completed a few more quests, but no change, i also tried an earlier save before i leveled, same result, must be a cap :(

yeah its a shame you have to use up all those points at the start to unlock the other branches i was hoping they would just unlock at level 10 in my 2nd playthrough so got to lvl 12 without spending any points and then had to use em all to unlock the other branches.