DVCPRO HD and Apple ProRes playback problem. Please help, my deadline is in 10 days

Hi there,
I tried looking in older posts, but couldn't find an answer.

In short, this is my problem:

Workflow: DVCPRO HD 1080i50 edited in FCP sent to Color, than sent back and at the end it will be down converted to PAL resolution (Digi Beta) for broadcast.

Problem: Everything is OK in FCP, but in Color picture jitter and plays like it's dropping frames (on comp screen and on broadcast monitor). Picture is also squeezed, but since is OK when it's back to FCP that's not a problem.

Video Output is set on Kona 625i25 8Bit to Analog Broadcast Monitor

Maintain frame rate is ON.

Same thing happening if Playback Proxy is on Full or on Quarter resolution.

I also tried to convert it to Apple Pro Res 422 1920x1080 50i via Media manager, but same thing happening.

My configuration is in my signature. I'n using 4 SATA 2 disc in my Mac (one for projects, one for media, one for rendering).

I can't figure out what's wrong, is my Mac to slow (but FCP plays it ok), or my settings are wrong.
Please help, it's quite urgent, I have 20 x 1 hour TV shows, first should be on the air in 10 days.

Also, if someone could tell me, should I stick to DVCPRO HD or keep converting to Apple ProRes.

Thank you

Seth

PowerMac 2x2.66 GHz Dual-Core Intel Xeon
5GB 667 MHz DDR2 FB-DIMM
NVIDIA GeForce 7300 GT
AJA Kona LHe
Apple Color 1.02