Linksys BEFVP41 & Netgear FVS318

New to the list.  Searched the archives for anything resembling the
subject without success.

Current situation: Two Linksys routers working fine (one static IP, one
PPPoE.)

Need to add another concurrent tunnel which Linksys doesn't support. 
Obtained a Netgear device but can't seem to get a usable connection
between the disparate vendors.  (According to the Netgear log a
"temporary" connection appears with the same parameters as the defined
tunnel, but that's as far as it goes.)

Can anyone provide some adumbration regarding configuration specifics
that might be hindering the process?

Thanks in advance,

John Nelissen