Linksys (WRVS4400N) Wireless Router

We bought this box to replace a BEFVP41 which started to show aging signs a month ago.
VPNs worked for a week after setting up the box.
IPSEC negotiation started to fail a week later. No parameters had been changed on the box and the client VPN boxes (which are Linksys boxes).
The box was shipped at 1.0.9. Web site says that 1.23 is available.
Firmware 1.23 on their web site is corrupted according to the firmware upgrade tool in the box. It sucks...
Issue is related to PPPOE MTU size negotiations versus fragmented packets.
First level support was arguing that packet size and IPSEC bad negotiation were not related. I found a Cisco document describing the impacts of a low MTU size on the IPSEC protocol. This shut their nonsense chattering. Cisco is the owner of LinkSys.
I took some time to get them traces and tests results to prove that MTU size had dropped to 1052 bytes which is much lower than LinkSys recommended minimal value of 1300. IPSEC has problems under 1200 bytes.
I told them also that the firmware upgrade on their web site is bad. No reaction yet.
My call has been routed to level 2 support people for more than two weeks now and no feedback yet. Not even an acknowledgement.
The wireless issue comes from the bad default parameters in the wireless configuration.
I searched fro 30 minutes in the LinkSys KB to find a solution. Beacon was set to high (100 Msec) and RTS Threshold was too high. The solution is not specific to this box however. Seems other wireless boxes from LinkSys have the same issue.
I am about to find an alternative and send back the box to the retailer. Given that we use Bell Canada's DSL link, I thought LinkSys would be eager to fix it but they do not seem to care.
Obviously they do not care.