Heyas, my first post and it's to ask for help :)

I just recently moved flat and brought my router with me.  My last flat had a TCL cable connection, as does my new flat, both belonging to different people (head tenants, feh).  The new flat's router is some crappy second hand D-link piece of crap that drops connection all the time, so my Linksys WRT54GL is here to the rescue! :D

Unfortunately, it seems that it's not quite that simple.  After plugging everything in and reconfiguring the router to use the new TCL connection settings, the intarwebs are unusable.  Now, I can feel my way around a network, but I'm no god, so here's the list of stuffs I did.

- Plugged the stupid surfboard modem (why make something light and vertical that plugs into a massive heavy coaxial?) into the router's Internet port and my PC's ethernet cable into a regular ol' switch port on the back of it.  'Internet' router status light blinks away, indicating that the router and modem can communicate just fine.

- Brought up my router's config page and changed its Static IP settings from the old IP/subnet/gateway to the new settings, as farmed from the old router.  While I was there, I changed the wireless network's name/pass to match the old, for the flat's convenience.  New settings show up in router's status page.  Restarted both modem and router for good measure.

- Everything shows up: router, both physically (ethernet) and wirelessly.  Other PCs on the network.  My PC in the router's connectivity list.  No-go on the internet.  HOW CAN I VIEW MY LOLCATS NAOOOO

- Win7's network center gives the skinny: PC connected via both ethernet and wireless to the router, grey line with X in the middle between router and globe representing the internet.  Diagnostics are useless as always: "idk, restart your modem or contact someone who actually knows lol".  By the way, I've been restarting both the modem and router quite a bit.

- After surfing around the router's settings, I come up with a blank.  Everything should work.  The IP settings are correct, I think.  There's nothing stupid enabled like DMZ or w/e that wasn't already working with the old TCL connection settings.  I perform a few stupid tests, like punching in a random IP and seeing if the derpboard modem still connects (it does, so I figure it'll connect no matter what and the router is the pimp in the relationship).  Disconnecting the modem from the router, to see if the connectivity lights dim (they do, on both modem and router).  Restarting everything a bajillion times.  Changing the router's IP from 192.168.1.1 to 192.168.0.1, because that's what the old router used.  Its status page plays dumb, listing only the settings; it doesn't actually test to see if they work. 

SOME good turn of event eventually happened: I Plugged my ethernet cable straight into the modem, configured the IPv4 LAN settings to use the TCL IPs.  Didn't work until I severed the wireless connection to the router, but after that, peachy.  I'm typing this on the connection as I.. type.  So I can verify the ip/gateway/blah are correct.

Ideas?  This router is fairly new, worked 100% perfectly at my old flat, hasn't been banged around or anything and has never failed me until now, so I'm fairly sure I'm just doing something stupid.