I researched my NV+ memory and acquired a new 1GB module as described in this post. Ran the Memory Test for a couple passes and all appeared Good. After a few days (NV+ continued to operate normally) I attempted a firmware update from 4.1.4 to 4.1.7, and during "Updating FW" the NV+ died/froze and after trying poweroff and reboot the symptoms appeared similar to a dead PSU as described both here and in another thread here. But the PSU was OK; c3po suggested "Corrupted BIOS".
When it happened, I chalked it-up to coincidence (the failure during "Updating firmware") but now I am wondering "might the firmware update process use the 1GB RAM in such a way as to corrupt the BIOS" or something.
Given I had to replace the chassis on my NV+, I'm now a bit gunshy to put-back my 1GB SODIMM. Wondering if it would be prudent for me to always have the 256MB module in place for firmware updates, then put the 1GB in for daily operation?