Accidentally flashed Ambit cablem modem with DD-WRT router firmware, please help!

[schismoid]

Hey all, I've got a bit of a strange one here. A friend of mine asked me to help configure her router (Linksys WRT54G v.6), since the wireless wasn't working correctly. When I tried to login at 192.168.1.1, I was presented with the "Management Mode" firmware upgrade screen, rather than the stock Linksys firmware, so there was no way to configure anything. I decided my best course of action was to proceed with installing the DD-WRT micro firmware. I'd used this in the past on this model of router with good success. I carefully followed the instructions as given here: bitsum.com/openwiking/owbase/ow.asp?WRT54G5_CFE
except that I started on step 7 because the router appeared to already be in management mode.

I flashed the router using TFTP, rebooted, and connected to find the DD-WRT firmware, and everything seemed fine. With one exception: the cable modem (Ambit model #U10C018) connected to the router seemed not to work.

After a bit of tinkering, I connected my ethernet cable directly to the cable modem, and connected to 192.168.1.1, only to find that...
The modem ALSO has the DD-WRT firmware on it! Further, the modem thinks that it's a WRT54G router, and obviously won't work as a cable modem.

Does anyone have suggestions of where to proceed from here? The DD-WRT interface allows you to easily upload a new firmware, so if I can get ahold of the factory Ambit firmware, I'd love to just revert to that. Alternatively, is there a good 3rd party firmware I could install that would restore my cable modem to working as a cable modem?

I feel like I really goofed here, so any advice would be appreciated. I've got experience flashing routers, but I'm a total beginner with cable modems, so go easy on me. Thanks!

[/24]

That is an odd one I would of expected a brick rather than a modem running DDWRT! do you have a max232? whats the console output as the device boots specifically does the bootloader shed any light on a possible solution? I don't think that you will be able to flash from the gui as it will check to see if it is a valid ddwrt image your best bet would be to head to the ddwrt forums and explain yourself there im sure if you can pursuade them to help you then either eko or redhawk would be able to create a bin file of haxorware you could flash with but you still have to be able to replace the bootloader so I don't know if that would be possible! the only other option is TSOP lift!