Hi,
I would go thru the router set ups and see if any of the "tweaks" can get you stable rather than trying another FW...I say this mostly beacuse 1.21 is considered to be pretty stable by "most" folks in here....that is by no means a 100% rating....but a pretty good rating none-the-less....
For starters, I have my router set up in Vertical (with power port at bottom) position as opposed to horizontal to assist with heat flow inside the unit. Then I have it plugged into my battery backup unit on a battery power plug, to help elminate any power fluctuations as potential problems. Start with wireless encryption disabled until you get the thing stable.
Also make sure your ISP modem is also plugged into the battery backup power source, in a battery supported plug.
Microwaves, fridges,,,and the like can interfere with wireless signals. ALSO check for 2.4GHz wireless telephones nearby....and any other wireless game controllers that use 2.4GHz signals....
In the advanced Wireless section of the setups, I use WLAN PARTITION - ENABLED (.11B and .11G and .11N devices are segregated by technology...IF I read the help file correctly)
Personally, I have moved away from .11B completely. I only use .11G and .11N wireless devices.
Hope soemthing helps.... I surely know how frustrating these disconnects can be....
SD1