I think Dell has a small problem with this issue; there are numerous forums on the web, as well as usenet posts, concerning the different panels installed in this LCD not meeting the advertised specs. I don't know how/why Dell would ship out of spec products when, if you get right down to it, that's tantamount to a bait & switch racket.
But I still can't imagine that Dell ran out of Samsung panels (if they were the original supplier for the 1907FP) and THEN put them on special using other panel makers -- with different spec panels -- due to demand. I think the different panels have been shipping with and without systems for a while now, and word of mouth on the variation, because someone discovered the problem and made it known, is reaching critical mass -- at least with PC enthusiasts.
I feel lucky (and good) in getting a Samsung panel: not because it's a Samsung, but because the other panels don't meet Dell's advertised specs and the Samsung does. If the other panels met the specs then it wouldn't be an issue. One poster says the software that came with the LCD told them the contrast ratio was 700. Software? How about going to the maker's web site? Anyone can put together a 'program' that tells you anything the maker wants you to know.
Computer items sell on brand recognition, price, and specifications. I think Dell is selling well on the first two, but I'm more than suspect of the last.