NMI: Parity Check / Memory Parity Error

Sounds like bad memory card.

BAD memory card

The first issue to clear up is that not all NMI errors are due to memory. Other boards in the system can cause this problem and components directly on the system motherboard can be at fault. But memory could be at fault most of the time for the following reasons:
-after 15 minutes or so, the system starts having memory errors.
-speeds are different between individual SIMM modules
-individual chips on the SIMM module are running at different access rates. Can be regulated somewhat by the BIOS and chip set of the system board if it allows you to lengthen the refresh wait states for memory access.
-Cache memory access rates were too slow and cause problems.
-contacts of all boards and SIMMs should be cleaned. You can use the eraser of a pencil to do this, thus ensuring good contacts. Be certain that all boards are firmly seated in their slots or sockets. Power supply can also cause many problems, thus, if possible, have the output voltages checked. Monitors can cause strange behaviors on your system as well. Use Surge Suppression power strip.

NMI: PATITY CHECK/PARITY ERROR

Try changing out you NIC.I have seen the Intel 3C90x series nic cause this error message on Dell poweredge and on lattitude systems via a docking station.