[j-nsp] m10 RE-2 memory upgrade troubles

[David Ball]

   I have an M10 (note: not an M10i) with a single RE-2 routing engine
which is hitting its head on memory (256MB).  I decided to take a
chance and purchase 2 more 256MB ECC low-profile DIMMS (Kingston
memory...I know, I know) in hopes of replacing the single that is in
there (which came with the router).
   The router booted, but only showed that it had 256MB instead of the
expected 512MB.  It also mentioned that it was non-ECC, but this was
resolved by placing the DIMMS in slots 1 and 2, and leaving 3 blank.
(as per a posting I read earlier tonight, but which I can no longer
find).  The memory then showed as being ECC w/hw something-or-other
(which is desired).
  Anyhow, I couldn't for the life of me get it to believe it had
512MB.  Even tried adding the original DIMM (to give it 768 and occupy
all DIMM slots) but it wouldn't even boot, as somewhat expected.
  Aside from "you should only use Juniper RAM" and "you should upgrade
your routing engine", does anyone have any ideas or direction?  Would
a BIOS upgrade help at all?  This is simply a band-aid fix until our
T640 network is deployed at which point we can retire the m10s, but
for now, we need em.  The RE-2 is no longer supported by Juniper,
hence my asking you good folks.
  Thanks in advance.

David