I've re-caulked a floor to wall joint in a tile shower enclosure 3 times in
2 years and it keeps coming loose from the wall. It seems to stick to the
floor ok. Preparation each time consisted of washing with detergent,
drying, and wiping with methyl alcohol. The caulk used the last 2 times was
a "siliconized" acrylic. Don't remember what I used the first time. Mold
is not a problem.

Is there some kind of caulk (white) that has better adhesion properties, or
is there a better way to prepare the tile surface?