MacPro 1,1 Random error, memory related?

I have a 1st Generation MacPro 2.66ghz Quad with 3GB of memory (4x512mb CTO) plus an additional 2x512mb

RISER CARD A: 4x512 (2xfactory & 2xOther Apple Memory)

RISER CARD B: 2x512 (Factory)

Sometimes the top riser card will flash a red light (solid) i then pulled the ram and sometimes it will still show a solid red light and when i pulled them switched them it would appear then disapper on occasion

i ran the apple ahrdware test a few times in loop mode; here is the only error i got:

http://img294.imageshack.us/img294/5364/mpramerrorfd9.png

4MEM/42/40000001: B: 1 C: 1 R:0


all the sticks of ram were from Apple, the additional sticks of ram i purchased from a friend who was upgrading his macpro and they were working flawlessly since October 2007 (macpro was purchased in feb 2007)

I recently relocated and started right when i first got my new location set up, nothing was damaged in the transfer as far as i know the macpro was solidly packed as if it were originally sent and nothing on it or bumped into it.

im not sure if its a riser card or memory.

upon apple hardware tests it does detect all 3gb of memory but gives methat random error.

ive only had 3 BSODS and 2 Kernal panics since ive had this machine.

anytips or help would be appreciated