bath tub wall kit

Installed a tub wall kit and have used polyseamseal kitchen and Bath Ultra. This was a new wall kit with an existing tub. I scrapped (with razer blade) and thoughly cleaned (with alcohol) before installing the caulking betweeen the walls and tub ledge. I heated the room to 80deg to ensure curing and still the seal between the tub eventually starts to pull appart. If I press it down it will look sealed and not come back up until the next shower. I am thinking after removing existing caulking I will sand the tub surface with 80 grit sandpaper and wipe with acetone. My question is will the tub walls be able to handle the acetone? Also what is recommended to use. I really think I should try another brand of caulking. I was thinking GE II 100 percent silicone. Any thoughts?
Thanks,
J