I have an Ignition DDR pad, a model with foam inserts. I was starting to notice unregistered steps from the left arrow when I knew I stepped on it. I started "testing" it out by repeatedly stepping on the arrow and observing how it registers with the game. It turns out my left arrow was indeed missing steps and getting "locked up" or "stuck". I would repeatedly step on it (the steps wouldn't register) then i'd stop, then I'd noticed a bunch of left arrow steps registering without my foot hitting the arrow.

I decided it test if it was really my pad by removing the foam inserts and playing the same songs on the pad. The pad worked like a charm, likely meaning the position of the foam inserts was somehow screwing the pad's censors. After some rearraning with the foam inserts the pad went back to working normally. I actually had a little multi-hour DDR marathon early today, wearing myself out, but my pad remained reliable, thank goodness.

Unfortunately, as the problem has been resolved, another one has risen, my PS2, probably for the 3rd time, is beginning to have some difficulty reading discs, especially with Virtua Fighter 4: Evolution which I just happen to be deeply into right now. Its kind of annoying. At its current state, the perfomance is excusable, but if it gets worse, I may just have to send it back into Sony. I hope Sony (especially with rumors the PS3 initial price tag) is designing PS3 to be a more reliable machine than its predecessor.