Another test round using 3518 in 64bit mode (& this time started everything from scratch - no existing vg or config/setup), and replicated the last-port issue, & logs sent to support@open-e.com.
Summary:
- RWC detected MegaRaid agent/device on eth0 & eth1 ok, but login fails on eth1
- Raid vd degradation status changes were correctly logged and notifications sent this time

All in all, a good result considering the previous confusing results, hopping betwewn versions 3278, 3518, & v6updt4, and trying both 32 & 64 bit versions of each. Cheers.