XSan Setup Issue

A technician from Tekserve left frustrated today and we can't figure out what the issue is. for some reason, the xsan won't recognize two of machines we're trying to attach to it. We're trying to setup a new Xsan system with a new 16tb Xsan2. On a March 09 Eight-Core MP, it worked perfectly. For the two machines that the Xsan won't recognize, the specs are as follows, running OS X 10.5.7

Model Name: Mac Pro
Model Identifier: MacPro1,1
Processor Name: Dual-Core Intel Xeon
Processor Speed: 2.66 GHz
Number Of Processors: 2
Total Number Of Cores: 4
L2 Cache (per processor): 4 MB
Memory: 2 GB
Bus Speed: 1.33 GHz
Boot ROM Version: MP11.005C.B08
SMC Version (system): 1.7f10

and

Model Name: Mac Pro
Model Identifier: MacPro3,1
Processor Name: Quad-Core Intel Xeon
Processor Speed: 2.8 GHz
Number Of Processors: 2
Total Number Of Cores: 8
L2 Cache (per processor): 12 MB
Memory: 8 GB
Bus Speed: 1.6 GHz
Boot ROM Version: MP31.006C.B05
SMC Version (system): 1.25f4