Memory in 3rd slot == Smoke?

[xbskid]

I had just gotten my mobo back after RMAing it in the middle of December (Apparently it was a problem with my memory and not the motherboard). I've learned that lesson. My Kingston stick is bad, and my Ultra stick is still good. But anyway, I just got it back last night and I noticed the bandwidth that Memtest86 reported for the memory was different for slot 2 than it was for slot 1. It reported the memory in Slot 1 as 609MB/sec, then Slot 2 as 578MB/sec. So I decided to try slot 3. (Note that I'm only using one 512MB stick at a time). I seated the RAM, turned it on, and I see smoke billow from the corner nearst the DIP switches, so I quickly cut the power. I showed my brother the area it came from, and he said it was a power converter for the third RAM slot. I talked to someone online, and he said it was because the RAM wasn't seated correctly. Needless to say, I have to RMA the board AGAIN, but what I'm asking is for clarification on the varying speeds of the slots, if RAM in only the 2nd or 3rd slots is unhealthy, and what (if anything else) would cause the barbeque to happen?

 

Note: I was only working with the motherboard, power supply, CPU (obviously), a floppy drive, and a USB keyboard.

[Angry_Games]

slots closest to the NB might in theory give slightly more bandwidth as it is a path with less distance (and resistance)

 

but in reality they should give the exact same bandwidth regardless

 

the bbq could be either defective board or incorrect installation of the board (shorting out on something etc).

 

RMA it

[xbskid]

Interestingly enough, Before the bbq, I had the bad stick in the third slot, and it reported 613MB/sec. And I replaced it with the good stick in hopes that I'd get better performance than having it in slot one. Cue the bbq. Should've included that in my original post.