Check out this quarter (at least that's what the slab says). Now thats a quality TPG! http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140493912811&ssPageName=STRK:MEWAX:IT#ht_1455wt_894
The seller seems to be putting down NGC. I am not aware of widespread NGC problems putting the wrong denomination on slabs. Questions and answers about this item Q: Why is this coin in a washington quarter 25 cent sleeve? A: Simply a typo. This happens occasionally. We have seen this on NGC holders as well. The grade on the holder is for the coin in the holder. Jan 02, 2011
Its actually a double error, struck on the wrong planchet and with the wrong dies!!!. Oddly enough these are quite common but extremely hard to spot.
Well you CAN find the same type of typo errors on PCGS, NGC, ICG, ANACS and probably all of the others as well. So I guess all the TPG's are of equal quality.
For what it's worth, that coin looks properly graded to me. While DGS wasn't a well known TPG, from what I've heard and seen, they were very accurate with their grading.