AW.getTop(element)

in IE it returns absolute cell position
In safari or chrome it returns relative position (includes scrollpos of datagrid object)

Yes, this is AW bug. Please use the patch from this topic -

http://www.activewidgets.com/javascript.forum.25143.2/combo-poblem-on-safari.html

Will be fixed in the next release.

Fixed in AW 2.5.5 -
http://www.activewidgets.com/general.bugs/2-5-5.html