Hiya James,
I've run some very limited tests with these mics, but not miced a full drum kit.
Firstly the output impedence on these things is 600 ohms. This is karokee mike territory and I'm always very wary of mikes that run at 600 ohms. It's more usual for microphones to be 300 ohms if they are manufactured for more professional use. What this means is that the output signal is very loud. Much louder than any of your normal microphones, which takes some getting used to. Yes you need to set the levels very low, however, they should not be distorting at low levels.
As regards the sound quality, I've run some limited tests. They sound totally horrible on the hand drums I was hoping to use them on, and I have any number of other microphones that are better for that. What's more when testing them with the more midrange stuff I found that the microphones were not only poor and flat sounding but also there seemed to be a bit of inconsistancy in quality between one of the microphones and the others. So it looks like there is definitely a variable build quality thing going on. (Tho maybe I am being unfair as they are drum mikes and not really for singing into etc, anyway)
[NOTE: I think this was kind of unfair, one of my mikes sounds slightly different to the others, it's a really marginal thing tho and not any kind of big deal I expect.]
However, I then tried the microphones on some full sized toms, where the sound quality seemed much better. It seems to be like they are skewed quite heavily to bassy stuff. I probably wouldn't want to mike a guitair cabinet with one, Maybe if you were running bass thru an amp?
The microphone I tried did not distort, although I was only playing one tom and wasn't exactly going wild!
They seem very low on handling noise if you hold them and sing into them!

I wouldn't especially want to sing into one of these things tho!
I did notice when doing these tests, what an unbelivable pain it is to set the levels, if there is only you and you are the one playing the drums! You really have to get the levels right on these microphones and it's hard to do so without constantly running back and forth.
As I say, I've only done limited testing and most of it with one microphone.
I'm assuming your problem is because of the impedance, but it might be that you have got a faulty microphone. I assume your other microphone is fine through the same cable?
If you do get the thing working, I'd be really interested to hear about how it sounds on the kick drum. I notice that it is described as being a kick drum mike on the spec sheet. Obviously at the moment, if it is distorting on toms, the idea of sticking it in the kick is preety wacky.
I'd be really interested to hear of your further adventures with this mic if you get anywhere with it.
love
Freya