P5B Deluxe resets when 2nd computer on LAN shuts down

[smackDAB]

I have a strange problem in my home network. I have 2 computer systems, one of them (P5B rig) a recent upgrade. By themselves both systems are rock solid with no strange behaviour. If both systems are up and running there is no strange behaviour. However when I shut down my A8N32 system my P5B system will often reset itself about 30 seconds after the power goes off on the A8N32 system. If I just restart the A8N32 system there is never any problem. Shutting down or reseting the P5B system has not impact on the A8N32 system.

I am not sharing any files or printers between the systems. They are in different rooms in my house. The common points for the systems are the "2Wire" DSL modem/router used to share the internet and a Ximeta LAN drive the two units share for backing up files.

Prior to upgrading to a P5B rig I had an old ASUS A7V333 system that shared the network with the A8N32 system. There was never any issue with resets or file sharing.

The 30 second delay before the reset looks to me like something is timing out but I have not been able to figure out what it is.

Any Ideas?


System 1:
Asus P5B deluxe mobo, Intel Duo E6600, eVGA 7900GS video, 2GB OCZ PC2-6400 memory, Windows XP Pro, Seagate 320GB SATA II drive, Enermax 535W power supply, APC 350 battery back up, Sony DRU-710A dvd, LAN plugged into Marvel Yukon 88E8056 LAN port

System 2:
ASUS A8N32-SLI deluxe mobo, AMD X2 4400+, eVGA 7900GT video, 2GB OCZ PC3200 memory, windows XP pro, seagate 320GB SATA II drive, Antec TruePower 550 power supply, APC 750 battery back up, Plextor PX-760A DVD, LAN plugged into Marvel Yukon 88E8053 LAN port

Network modem & switch:
2wire 2700 HG-E DSL modem & 4 port switch

LAN drive (seen by both systems)
Ximeta 120 NDAS