i had the same problem with my DD-WRT WRT54GL going on, so i did a little research and come up with a nice solutin: ipcop > a dedicated old pc machine that i had in spare (Pentium III 733MHZ, 2x256SD-RAM, 6GB 2.5" Notebookhard disk ide with adaptor, 125Watts Psu, 2x intel ethernet card and a matrox graphical adatper pci)
my ipcop is a router and proxy at the same time, it filters..
easy to use via web interface and good hardware support
i build in total 10 of them for local "Youth clubs" and friends of mines to stay 24/7 connected within more than 10 clients behind the router
greetz
serhat from germany