Replicator 2x is destructing its build as it prints

[Themoonisacheese]

I dont quite know how to put it into words, but basically, we have a Makerbot 2x at work, and it has several problems.
the first one seems semi-random, and is just the extruder clogging itself, but a 240°C extruding temp seems to do the trick. we have also printed all the spring loaded extruder parts in order to replace the stock one, we just need the spring.

the second one happens only when printing huge surfaces, such as a raspberry b+ case.
what happens is, the filament from a layer (usually the 2-3rd one) starts to peel off, and the extruder grabs it as it goes and it causes the case to have a hole on it (see photos).


we are printing at 240°C with the build plate heated at 120°C
printing with black abs from makershop

tl;dr: filament from a early layer peels off when printing large surfaces, and this is... bad?

EDIT: photo has been compressed, here is the full version: http://www.hostingpics.net/viewer.ph...78864board.jpg