AIR1 v AIR2 v Spark

[Rufus McDufus]

OK, I've tried a few things. PC connected directly to Devialet 200 via one single cat 5e cable.
Firmware 8.1.3 on Devialet, AIR 2.1.4-beta4. Playing music using iTunes. I just used 16/44.1 CD rips.
Windows 7 64-bit Ultimate on PC. I couldn't be bothered to type the specs in so image capture of 'hwinfo' below. System was a pretty decent gaming PC 3 years ago and probably moderately overclocked. Most services including AV disabled. I tend to run the system pretty lean anyhow.

Firstly I tested various nmap portscans of the Devialet while playing music - intense, w/ UDP, all TCP, slow comprehensive etc. etc. Nothing produced any issues.

Next I went back to testing the display power off/on (via Windows 'power options'). In High Performance (which I always use) with the display set to switch off after one minute I managed to get AIR to crash completely when moving the mouse to power the display back on.
I then had trouble reproducing any issues so set the power plan to 'Balanced' with screen switch-off set to 1 minute. OK, when display powers off I'm starting to get stutters in the music. Big stutter sometimes when moving the mouse to re-enable the display.
Switched power plan to 'Power Saving' w/ display switch-off set to 1 minute. Now I'm getting constant stuttering - though again only when the display has switched off after 1 minute. Stuttering is constant like the volume is phasing up and down several times a second. I have to restart AIR to fix it. Went back to High Performance plan and couldn't reproduce problem again and got bored.
Task Manager showed barely any system load or memory usage all throughout.
There does seem to be a link with power options and particularly with display power off/on. I'm wondering if the graphics card is a factor here?

Interestingly I have a 2008-vintage Asus Eee PC and it never has any problems with AIR.

Here's the specs. Graphics card is AMD Radeon HD 7950 with latest drivers.