The 1995 CBS/FOX VHS releases have the correct pitch audio, as well as the 2001 Warner/BBC DVD (don’t know if that release has the altered audio since it was released after 2000; we actually rented that DVD from Netflix in 2006 back when they were doing DVDs by mail). I’m not sure why the CBS/FOX DVD version has AGDO and TWT running at 24 and ACS at 25, why couldn’t they do pulldown on AGDO and TWT like ACS?
After ripping my 1999 DVD, AGDO and TWT run at 23.976, but ACS plays at the original 25 fps (even though it’s an NTSC release, 720x480, NOT 720x576). Luckily I grew up with the 2001 Warner DVD back then and remembered the pitch it was. After trying to watch W&G years later, the audio didn’t sound right until more than a year ago I found out that Aardman shot the films and did post at 25fps instead of the standard 24fps.
Honestly, if they really wanted to go 24fps, at least keep the audio the same. It’s just like 24fps get sped up for PAL regions at 25fps and the film audio is sped up, except it’s the reverse. We’re watching the film at an incorrect speed!
Is it possible, though? If I remember correctly, whenever a PAL (25p or 25i) source is converted to NTSC (24p with pulldown to 30p or 30i), most companies opt to convert the 25 frame/field-per-second source to an interlaced format (the aforementioned 30i), even if it was shot progressive (i.e. on film). In most instances of this method, the pitch of the original source is kept intact; could converting a progressive PAL (25p) source to progressive NTSC (23.976/24p) bring similar (if not completely identical) results? Many of the posts on this thread suggest that most U.S. home video releases of the “Wallace & Gromit” shorts present each short converted incorrectly.
(Oh, and one more thing: don’t you actually mean 640x480? The video of an NTSC DVD is indeed stored at 720x480, but is scaled to either 640x480 (4:3) or 853x480 (16:9))