Opinion, please

The company my wife works for sent us a Netgear FVG318 Prosafe VPN
router for inclusion into our network here at home. The current
configuration is:
Netgear something modem gateway provided by Road Runner Business
class
Netgear FVG318 VPN router with static IP address (no wireless feature
activated) Used as VPN tunneling device to their facilities and also
as DHCP serveron the LAN side.
Linksys WRT54G set up as WAP (no connection to WAN port) for our
wireless devices
Linksys RTP300 VOIP (Vonage) router connected into one of the
WRT54G's switched ports

We have 3 wireless PC's and 2 wired. No problems here. We ahve run
the network minus the FVG318 for 2 years without problems.

The problem is that the 318 drops its Internet connection randomly
and frequently such that the RTP300 is NOT seen by Vonage and phone
calls to our home phone are forwarded to my cell phone which is the
number to use when the network is down. I have checked and my home
phone is NOT forwarded to my cell. Sometimes one can call the home
number and when they are forwarded to the cell, just hang up and
redial the home number and get through to thew Vonage router and then
to our house phone system.

The bottom line here is that I have discussed theis problem with Road
Runner and Netgear Tech supportm and Netgear seems to think the 318
is not fast enough for 10 mbit on the WAN side and 54mbit (or
thereabouts) on the LAN.

The engineers at my wife's company are convinced that the 318 is the
problem and currently is at a dead end, and have offered to send me a
Netgear FVS338 in its place.

They use Sonicwall at their network centers and I said we would take
one of those, but they said it was not economically feasible
(shucks), and the FVS338 will do the job for us. That's what they
said when the FVG318 arrived.

Anyone with FVS338 experience have anything to say about such drop
outs? ?

Your opinions are appreciated.