This Field Notice was just updated about a month ago.
http://www.cisco.com/en/US/ts/fn/631/fn63132.html
There are 4 ways to find out if your DIMM's are part of the FN.
1.) What you're doing is correct and should work
2.) Use FM 3.4.1z and use the TOOL, then DIMM Check Report
3.) Visually inspect the DIMM's by putting the supervisor into "out-of-service" mode and pulling out the sup.
4.) None of these worked for me as we were already at 4.1.1b looking at upgrading when I found this FN. I
opened a case with TAC and they gave me 2 commands to run via the CLI to let us know if we were impacted
by this FN. I don't know if the commands will work on SAN-OS 3.x and I can't recall the exact commands at
this time but it was something like show module 6 and show environment module 6. When I get back
to the office I'll see if I can find the email that I got from TAC with these commands.
Gary