We've had about 4 or 5 customers come in over the past year and mention to us that the round brown 3M bumpers suddendly start to melt and leave a long brown drip mark down the wall. I've gathered that this is not caused by heat or anything and the melting bumpers are usually about 8 years old. Has anyone ever heard of this happening? After the second person came in to our store complaining of this, I called 3M and was connected to a lab tech., who told me that he has heard of it but not enough of it to warrant them actually looking into it. Luckily noone was seriously angry at this happening, since apparently the brown drip is next to impossible to get off the wall. Maybe if enough of us have had this happen, 3M will change their bumper recipe!!!!!