Video sometimes plays in a jerky/jumping motion

[innerspace]

I have been experiencing problems with video files freezing/jumping, video seems to reduce to about 1-2 frames per second. The sound plays fine and the problem can be fixed by simply restarting the software.
There are no patterns of when/why it occurs(mpg, mov, avi all cause it, sometimes at the start and sometime in the middle of videos), but I have finally isolated it to a vlc problem.

I have a rather strange setup, running a custom built TV broadcasting system - any suggestions will be welcomed.

Heres my system info:
Asus MB(cant recall version)
Intel core2duo 2.0ghz
1gb DDR2 ram
Asus EN7300LE using vga monitor and tv out(PAL)
Vista HDD setup: 320gb SATA
XP HDD setup: 120gb IDE(xp, vlc, software only) + 500gb SATA(video library)

Version 1 of my software was made in delphi using the vlc activeX control.
Version 2 was made in c# using the libvlc dll and c# wrapper.
I know that this error is not with my software since it works flawlessy in other environments and the problems transfer to the standalone vlc player too.

Originally I was using version 1(delphi) on windows vista home premium. no problems(well not along these lines!)
I decided to change to xp sp2 since vista drained unnecessary resources, and developed version 2(c#) in an xp environment.

When I installed xp my software version 2 wasnt complete so I continued using version 1 for a while.
Shortly after the video started with its erratic behavior, playing with jerky motion.

Hoping that the problem was with version 1 and xp incompatibility i completed version 2 in c# which works fine on my development machine (laptop, xp sp2) and upgraded.... same problem.

Initially I thought driver compatibility problems, uninstalled, reinstalled, disabled write combining - no change.

Today I tried a new test, waited for the jerky movement to start in my software and opened a video in wmp - played fine. opened the same video in vlc (while another vlc process was running the jerky video in my software)- jerky movement.
Which to me says that it is not a graphics card problem but a vlc problem (yes, possibly vlc-graphics card confilct, but vlc related none the less)

My problems are made harder since this system is in a different continent to me and I am having to debug it remotely. I use logmein for remote access and have staff monitoring the system to report problems and whats happening during my tests.

I was about to remove vlc (plus configuration settings in app data) and give a fresh install, just as the scheduled shutdown kicked in. will try that in the morning, but wanted to see if anyone had ideas as to the cause in the meantime

The current output module is opengl, I will try different settings but I was previously forced to use opengl due to another program I have running.
This is a custom built monitoring program(made in delphi), which restarts the tv software automatically if the image on the screen doesnt change for 3 minutes.
When using anything other than opengl the monitor is unable to recognise anything from the vlc output.

Most of this problems have occurred on the tv output of the graphics card (which is in turn broadcast over a cable tv network).
I believe that this also occurs on the vga monitor but am yet to 100% confirm this, will check this soon.

While vlc is jerking inside my software other parts of my software (a text scroller) seem to run slower. opening a different video within vlc itself displays the same jerky motion. Restarting my software solves the problem.
(Just thought of a new test to determine what actually fixes the problem - opening another vlc video, expecting jerky motion, then restart my software with the other jerky vlc still playing....will try it tomorrow and post results)

If anyone has experienced similar things, or has any ideas as to the cause/solution to this problem your help will be much appreciated.

Version 2 (C#) of my broadcast software will eventually be released as open source software for anyone thats interested.
PM me with your email if you would like to receive notification of release. I just need to resolve this and a few other issues, plus neaten up and make comments understandable to people other than me!
The software is a video scheduling and broadcasting system, with built in video advert and scrolling text advert features. Purpose built for my companies needs (local TV) but adaptable for other purposes as well.

[innerspace]

Almost forgot a key bit of information - although cant confirm it now because the computer is in its scheduled bedtime.

VLC version is 0.8.6 and (I think) release h

Will install 0.8.6i tommorow after removing all traces of vlc

[VLC_help]

You use nightlies or current stable VLC in your program?

[innerspace]

I use the current stable release. I was using 0.8.6d but have now upgraded to 0.8.6.i

For anyone that is experiencing similar problems i eventually identified the problem to be with opengl and some problems with my Nvidea 7300 drivers on XP.

As mentioned in the previous post opengl worked perfectly with my vista setup on the same hardware.

My solution was to change to directx3D, which on my vista version HADNT worked (cant recall whether it didnt work at all or just didnt work with my monitor program, which took a sceenshot of the vlc window to check for movement).

Opengl, directx3d and asciiart were the only modes in vlc 0.8.6i which displayed an image in the screenshot.
OpenGL caused intermittent freezing, asciiart is a nice feature but not great for TV, lets hope that directX3D continues to run smoothly.