Okay, you said "But when I turn on the DSL, the R4 isn't detected and won't auto start. I just get the main DSL menu". So it looks suspiciously like a connector problem.
Just to exclude all other possible problems, just remove the micro SD card from the R4. Then put the R4 (without the SD card) in the DS and start. The DS should now display: "Couldn't find the SD/TF card". If not then the DS doesn't see the R4 and nothing you will put on the SD card will change that. So toying with the Panasonic SD formatter, Wood R4 versions, different SD card or whatever you try will not make any difference. You will first have to solve this problem.
You already "cleaned" the contacts by blowing in the slot, so most likely the problem is that the contacts of the SD just doesn't reach the R4. The contacts of the R4 are a tiny bit lower than a commercial card (I guess to create enough room for the chip).
Your card is not the first with this problem. A way to solve it is known as "the paper trick". Take a look here what this means:
Paper trick on GBAtemp.net. Just a small piece of paper below the contacts to lift them just a bit. When you now try to start without the SD card you should see the "Couldn't find the SD/TF card" message. When that happens, try the SD card again, format it and put the latest Wood R4 on it as you did before. I'm sure you already had it right the first time, it is just this contact issue between the R4 and the DS.
Note: it is likely that the R4 even works in another DS, these are just small differences between DSses and you are just unlucky.
To be sure: you use a DS phat or DS lite? If you use a DSi or even newer DS then the DS will also not see the R4, that is because the method used by the R4 to gain control does not longer exist in the new DS versions. But I assume you know this...
