anybody know what determines when tight is tight enough and "if tight enough" what is it that makes certain the lateral play is not excessive or lacking to some degree. i know how shimano does it, and Campy, but not FSA. something MUST determine how far apart the shoulders of the crank are so as to match the BB/shell/bearing width. AFAIK, it is critical to within a few thousandths of an inch, unless...

okay did some digging...

looks like FSA might use the wavy washer (like some campy cranks) and just accepts the idea that a crank that is spring loaded is satisfactory for practical use. so OP could have an overly wide BB shell that is too wide to satisfy the requirements (unlikely due to the fact that is was working) of a wavy washer, or the wavy washer has given up the ghost.

i think i've seen this movie before.