DVD Compatibiltiy .... Again !

briefly...

I need recommendations for Set-Top DVD recorders which offer
the maximum playability/compatibility when disks are distributed to other pc/mac/set-top players.

i dont mind too much about machine cost, i would even be prepared to buy a "pro" machine, i just need the most reliable solution.

some more background info ...

I'm familiar with DVD Authoring, I normally make DVDs in DVD studio pro.
I know that DVD-R disks (etc) cannot be guarranteed to play back on all pc/mac/set tops.
I have used a pretty low data rate, so this is not an issue

I shoot in PAL (i'm uk based), and deliver NTSC VHS dubs to my clients in the US. -
these dubs are always between 1 and 2 hours long, and each job has many hours of footage.
now my US clients are asking for DVD instead of VHS. (no authoring/menus required.)

i have already tried the set-top approach, with a Pioneer DVR 520H (DVD-R).
it works fine, creates region 1 disks fine , however, when i try to play the disks back on other machines, i get weird results, with only about 60% success.

i know this is common, but there must be some people out there who can recommend a "least bad" solution, or maybe someone who's done more tests can tell me some of the pifalls of set-tops that i don't yet know about.

thanks,

Cowpat