Severe audio sync problems Mbox2 Pro

[mezza9]

Hi all!

I'll post the same here as I'm emailing to tech support, to see if someone has similar problems:

Audio Interface: Mbox 2 Pro
Digidesign Software: Pro Tools LE
Version: 7.3.1
Computer Model and Speed: CPU: AMD Athlon 64 X2 4800+ / MoBo: Asus M2N-SLI Deluxe
RAM: 2Gb 533MHz DDR2 dual-channel
Operating System: Win XP Pro SP2

Other Digidesign and third party products used in the system:
Ext. firewire harddisks by LaCie and Western Digital, M-Audio Keystation 49e midi keyboard, Fostex FR-2 field recorder

Please give a concise description of the problem:
-Mbox2 Pro doesn't output audio after launching Pro Tools before I change from internal to wordclock or s/pdif sync and back to internal (I don't have other digital devices or a master clock in the system, so no incoming sync to those)

-PT LE often fails to initiate playback, flashing the play and stop icons in transport, but remaining stopped. Moving the playback cursor to another location may help, but also may take several attempts before playback starts -sometimes during playback there is a pop and a short pause, after which the playback continues but the screen freezes and doesn't show playback progress. After stopping playback it returns normal

-after approximately 15-20 minutes of work, the audio sync drops off and the audio being played back becomes corrupted. To remedy this, it is necessary to switch between ext. and int. sync again. After a couple of times doing this the rate it comes up gets faster and it is better to reboot the system.

-every second time I'm bouncing to disk (recently a lot to mp3), the bounce plays back normally, but the file is not saved. I have tested different Playback engine settings with not much results. Also tried convert during/after bounce, which doesn't affect the problem. Sometimes though with a long bounce, the real-time conversion is not even possible.


Troubleshooting already attempted:
Installed AMD Dual core optimizer, installed Win XP dual core hotfix and did the registry edits, tried different combinations of PT playback engine and hardware settings, disabled unnecessary devices from Windows device management.

Now I decided to try one more thing: using external sync via s/pdif from the Fostex FR-2's digital output. The unit is equipped with the optional timecode card and should provide very accurate clock. This removed all the problems and the system is performing very stable and accurate. This would point the problem to be the Mbox2 Pro's internal sync clock?

Question: does it mess things up if I continuously work using the external s/pdif sync? I remember from my studies when using Mix24 TDM system, that we were guided to switch to s/pdif sync for recording via s/pdif, but then return back to internal once done with recording and starting editing and mixing. I've got about 7 years of experience with PT on different platforms, so the basic tricks I've pretty much exhausted. At the moment I've got a working setup at the moment thanks to the FR-2, but I can't have it always around the computer.

Thanks in advance for any help and advice!

[mezza9]

Anyone? No reply from tech support so far either...

One update though: The system does indeed run quite stable with the s/pdif clock source otherwise, but bounce to disk is still a problem. I would say that 3 attempts out of 4 result in no bounced file being saved, and I have no idea what makes the save succesful when it happens?