mozilla / firefox div height issue

[sneaks]

my problem in mozilla occurs when i have relative divs vertically one following another. the problem is that the div titled contentBtm only displays correctly when i give the hardcode in pixels the height of the bottomwrapper div otherwise it floats at the same vertical position as the wrapper... i really want to be able to have the height be relative to its content...

#bottomWrapper {
width:745px;
height: 200px;
}
#contentBtm {
height: 12px; 
width: 745px; 
background-image: url(../images/745_btm.gif); 
background-repeat: no-repeat;
}

hope i explained this problem okay...

thanks!
jonathan

[sneaks]

and in my weakest moment, a voice in my head spoke:
clear: both; (on the contentBtm div)...

snx