ha i had the exact same situation with crank bolts last week. such a duh moment.

i've also had problems with the cranks not fully contacting the spindle--make sure the taper is clean and no slipping/rounding is occuring. (&jis/iso compatibility...)

all these instructions refer to three piece bottom brackets. with sealed cartridge, you can crank down on them. i have also had recent issues with my italian bottom bracket--use a thread compound on the fixed cup so it doesn't back itself out (which is the fault of the threading in italian jobbies) which probably doesn't apply in your case, but yeah...