This is a permanent install in a nightclub. Server 2 has only recently begun acting up. The first night of failure being an incredibly hot and humid one. The problem has happened in both a hot & humid room and also shortly after a cold start in a fully air conditioned room with no bodies in it. Both Mac's are in cupboards with supplemental intake/outtake fans built into the backside of cupboard. This system has been running like nearly 3 years.

System 1 and 2 are both identical, except after checking the specs on both systems, server 1 only has 2 GB of Ram, and server 2 has 6 GB of RAM. Possible ram failure? Stolen RAM? I'll check inside tomorrow - using system tonight

model : Mac Pro
Model identifier : MacPro 3.1
Processor name : Quad core Intel xeon
Processor Speed : 3 Ghz
Number of Processors: 2
Total number of cores: 8
L2 cache (per processor)12 mb
Memory: 2 GB(server 1) (6GB on server 2)
Bus Speed: 1.6 ghz
Boot ROM Version: MP31.006c.B05
SMC Version: 1.25f4

Catalyst version PM 4.10_nm165UB_HD