The box says it is 4:3 full frame, but even when it aired on my local PBS affiliate as part of "Masterpiece Theater", it was letterboxed to 16:9. Does anyone here actually own the WB R1 release of this title?
According to a review at DVD Talk, the R1 disc is full frame (for some odd reason) and the R2 is in the proper widescreen (so why did R1 get cheated?!).
I bit the bullet and purchased it, and, horror of horrors, it is quite clearly cropped 4:3 as indicated on the packaging. As far as I know, it was never broadcast in this aspect ratio in R1, so I don't know why HBO/Granada/whomever would consider inflicting this on those of us in the USA and Canada. It's a great program, and deserves better.
PBS did air Prime Suspect 6 in 1.78:1 widescreen (16:9 enhanced for PBS stations that also aired it for HDTV viewers). I liked seeing it in widescreen (and would have bought the DVD if it was in widescreen).
To add insult to injury, the cast & crew interviews supplement is in 16:9 enhanced widescreen with lots of properly framed clips from the show that look much better than the actual program.