I agree. I have been with NBA for awhile. Their tracking 
has always been off. I know the ROI and EPC for every
keyword I'm bidding on for a given ad, lander, offer combo.
For many keywords, this ROI and EPC has come from 
thousands of clicks (a reasonably significant sample size). 
I have run the offers on NBA and other networks. The NBA 
ROI and EPC for the same keyword, ad, lander, offer combos 
are significantly lower than expected (i.e. 50%+ off).
These variances can only be explained by tracking issues.
Recently, this was admitted by my AM on one particular offer 
I'm running with NBA. Of course, with my data, my AM's
admittance was unnecessary.