Switching from DD-WRT to Tomato?

[Yorak]

I am using a Netgear WNR3500v2/U/L on DD-WRT v24-sp2 (08/12/10) mega - build 14929. This build has been great for the most part, but there are times when my wireless signal randomly drops. This desktop is only maybe 20 feet away from the router. My laptop is also the same distance from it, literally just around the corner with open doors. There are no devices (in my apartment, at least) that can be interfering with it. Perhaps the neighbor has something interfering, though. I am not going to say this is a firmware issue, but I figured I would take this opportunity to install Tomato Firmware on it. I wish to use this build via this guide.

Now please excuse my ignorance, but does the "U" in the model name make it a completely different router? I am unsure of what the "U" even means. Also, I remember when I first installed DD-WRT on it, I had to do it via a wired connection and have a specific static IP. In the guide (unless I am blind), it does not mention it. I cannot see how changing the firmware over wireless would even work, so I am assuming it does have to be a wired connection. What should the static IP be, then? Lastly, by reading this guide, it simply says I change the file extension from .chk to .bin for it to be loaded from DD-WRT. Is that true?

Thank you in advance. :)

[Yorak]

Okay, so when I tried to upgrade to the Tomato Firmware I got, "Upgrade Failed" after about 8-9 seconds. I did some research to see what may be wrong. It seems that going from a DD-WRT mega build to anything else should not many issues. I tried to flash back to "Netgear WNR3500 v2 Firmware: Special File for initial flashing", and that too failed. What am I doing wrong? I did a 30/30/30 reset, connected to the router with a static IP of 192.168.1.8, had firewall and antivirus disabled, no weird browser plugins, and was using IE as is recommended.

For what it is worth, I received the same error no matter what file I tried to "upgrade" to. Both the file with the .bin extension and the regular. chk extension. Luckily, I did a backup of my DD-WRT settings and did not brick the router, lol. So I restored them and am up and running again. I just hope somebody can point me in the right direction.