Bluray interlaced footage plays as progressive no matter what!

[Dimitris Mantalias]

Ok, here is a very disturbing problem I've got.

In our studio (we do wedding video), we have a setup combined of a 37'' LCD 1080p TV plus a PC (Windows XP, Nvdia 8500GT), so we can present our job to our customers, especially the HD. Here is the deal:

We have our BD iso image files, created by Encore or Sony DVD Architect which we mount with Daemon Tools. Then we use a BD software player to playback the Bluray. Problem is, although the footage is interlaced, all software players insist on converting to progressive. No matter what the player is (WinDVD, Showtime, PowerDVD or Total Media Theater) and regardless I check "no deinterlacing", the BD will play progressive.

Strangest thing though is that, if I open the iso file and playback directly the m2ts files inside, they will play perfectly interlaced! The problem seems to be with the BD structure as I can understand, but I can't find any workaround. I played with every possible setting in both software players and Nvidia settings but no luck. It wants progressive.

Another strange thing is that for example, if I have PowerDVD to "no deinterlace" option, it will still play progressive but with the known image distortions found when playing interlace on LCD. Still, PowerDVD will play perfectly the interlaced material from directly inside the ISO (m2ts files)!

Also, if I play the BD from a PS3, it plays as it was supposed to play.

I am very frustrated about it. Can anyone please help me finding a solution to that issue?

Thanks in advance.