I have a PB Superflash taillight (it might actually be the Smart equivalent) and if the road is wet it starts to do weird things. It will either turn off of go from flashing to steady and you can't turn it off or back to flashing. Road doesn't even have to be especially wet. I went for a ride this morning after a storm last night but for the most part the road was dry just with the occasional puddle which I tried to avoid and the light went to steady mode by itself. I pulled the batteries out and left it all day and it was OK again for the ride home.