it's not makerware that scales things down - it's an inherent property of abs.
Pla wth makerware doesn't do it.

Found that out yesterday. I sized my workbench plugs for abs and they were absolutely bang on my dimensions - so about 0.3mm too large in diameter for the holes. Sanded down okay though, and the next batch with adjusted diameter are bang on.

Printed them in both makerware and simplify3d and the measurements are exactly what I set in openscad from both programs. This never happened whan I used abs. Always had to compensate for the shrinkage
This is yet another thing I like about pla - the dimensions I set are the ones that get printed.

Basically abs expands when it's printed and then shrinks by 1%
This is why it warps a lot more than pla.

So to get an exact size print in abs I scale the entire print up by 1%.

But pla - doesn't shrink. The stuff I'm using doesn't anyway.

I know geoff likes repg - I used it once and switched to makerware. Much much better program.
S3d - is better - but it's not free :-) And the idiot mode really is for idiots.
Once I got a level build plate and got it calibrated properly and started using blue tape - I discovered that makerware was actually a lot better than I'd supposed :-)
Most of the issues I was having were purely mechanical.

But s3d is a lot better. I don't normally advocate buying software, as the opensource and freeware market is saturated with the stuff.
But s3d is worth the money - it'll probably pay for itself in a couple of years just in the plastic I won't have thrown away.

Once I get to grips with some of the more advanced features I can see it really starting to pay for itself.