Pads constantly show on wrong side!

I've been trying (unsuccessfully) to play step mania for over an hour now with my daughter, but NO MATTER WHAT, the pads keep switching sides <--> after pressing START!?! I don't get it. If I plug in both pads then start Stepmania, the right pad ALWAYS shows on the left side and vice versa. It DOES NOT MATTER if I swap control boxes, or dance pads, or usb cords, or usb ports! IF I start with the right dance pad and press Start, THEN plug in the left dance pad and press Start, it immediately says, NOT PRESENT and I can ONLY use the left dance pad. IF I start with the left dance pad and press Start, THEN plug in the right dance pad and press Start, it immediately switches sides (again) so the pads are reversed. Again, switching usb ports, usb cords, controll boxes, and dance pads have no bearing on this effect. Restarting Step Mania does not solve this. Restarting my computer does not solve this. This seems like an internal error of Step Mania. I'd like to just move one pad over to the other side when this happens, however my living room floor space does not allow this and one USB cord is longer than the other to account for this, so this is simply not an option to physically switch pads without unplugging anything once the game starts due to not having a long enough usb cord. A little help? I'd like to be able to play again, but can't unless I play solo!

EDIT: I just played and noticed something I'm sure someone else will try and say; when it says NOT PRESENT, it is >>right after<< pressing START from the main screen, not when selecting 8-pads single player, which also shows NOT PRESENT. Just wanted to make that clear, that these errors are cropping up off the main screen when selecting the player.