I have a WRT54Gv4 and i flashed it to DD-WRT v23 SP1. It seems very unstable as soon as I try doing some p2p downloads. By unstable I mean I can't route to the internet and when I ping my router it is very inconsistent. I followed this guide: http://www.dd-wrt.com/wiki/index.php/WRT54G_v4_Installation_Tutorial under "Access Restrictions" there's a box named "Catch all P2P Protocols". Should have that checked?