I purchased a D2pro and Wii-Clip from Mod Chip Central (I'm located in the USA, while they're located in Canada, if that makes a difference; possibly US laws preventing them from shipping it with firmware?). I've tried to put the Wii-Clip on a few times, and each time, the LED goes on, but backups will not play, only originals.

I'm starting to wonder if the D2pro came with firmware installed, or if I need to purchase a d2prog and install some firmware. Anyone ordered a D2pro from here? Maybe it's just the Wii-Clip and I should head over to RadioShack for a 15W soldering iron (my iron is 25W, will that work?) and some 30AWG wire?

not sure what the laws are there m8 but i can say ive used loads of those chips and not had any probs
are you sure the back ups are ok ?
is the chip wired for you chipset ie. if you got a d2b is the chip solderd for a d2c (only asking because ive known this happen before)

Yep, it's a D2c Wii-Clip and a D2C Wii. (It says D2C on the chip itself.) Purchased around Christmas last year.

I also got a response back from Mod Chip Central stating that the chips come with firmware pre-flashed, so that's not the issue. After trying 2 brands of media (Ritek and Verbatim) on 2 different burners (Optiarc and HP), I believe either the chip or the clip is defective and I've asked Mod Chip Central for a replacement chip (after I send the old one back, of course).

What you need to do is throw the clip away and get someone to solder it in!!

couldn't agree more