Thanks for your effort, but forget about Serva. This is pxelinux.0 calling pxechain for calling Startrom.n12.
Why are you trying to blame Serva here?
pxelinux.0 loads and runs ok.
pxechain says TFTP IP=0.0.0.0 when it should've got the right TFTP server IP from the PXE stack; can't you see that?
btw Serva log shows the last file requested and TFTP transferred was pxechain.
The Serva menu entry looks like
menu label ^4) Windows XP Home Edition, NTx86
where the append command starting with "::" means the TFTP IP address should be taken from the PXE stack, but that PXE stack has TFTP IP=0.0.0.0 then of course it cannot continue...
I really wonder how w/o having more info than this you can say "I still don't think your install fails just because it's not version 2.1"
Anyway I think DPM/ICOP should replace the 13 years old PXE BIOS module with a current one and we all can save future guess work on these topics.