Very odd sound behaviour

[Seabee]

I have a new EeePC 1015P - I wiped the disk and installed WXP-Pro Sp3 using the SATA drivers (as I could not live with W7 Starter). I installed the latest BIOS and all relevant drivers from the ASUS site and everything works fine except VLC 1.1.5 and 1.1.4 which both exhibited stuttering sound on MP3s and TS video played from the C: drive or a Network share.

I tried changing sound modules and fiddling about with other settings which made no difference. However I discovered that with an SD card or USB drive inserted before starting VLC the problem goes away. The contents of the SD card or USB drive don't appear to be relevant as they can be blank. If I eject the device with the tray icon while VLC 1.1.5 is playing the problem returns if I subsequently put it back the problem disappears again.

I have not noticed this with any other media player. It is not a problem keeping an SD card in the slot but I would like to know what is going on. I suspect it is a dual-core or SATA AHCI issue but don't have the knowledge to prove it.

[VLC_help]

Did you test with power cord?

[Seabee]

Yes. It made no difference.

[Seabee]

VLC 1.1.6 Fixed the problem with MP3s but the behaviour with TS video changed. With Power - no problem, remove power - problem returns, removing power while playing and reapplying it causes problem to appear and disappear.

Exactly the same results if a blank SD card is inserted or removed while playing. So does the insertion of an SD card cause it to switch to a different power mode?

[VLC_help]

So does the insertion of an SD card cause it to switch to a different power mode?

In theory it shouldn't but you can verify that. You can also check if CPU usage raises higher when SD card is inserted.

[Seabee]

This problem has returned with VLC 2.0.0 Exactly the same symptoms as before. Inserting an SD card, blank or with content makes it go away.