Trouble W/ Isis drive

I've recently installed a Full speed ahead Isis drive BB, to replace the original Tru-Vativ BB on my
cx bike. I thought the spindle sizes are to be universal in dia. However reinstalling the Tru-vativ
crank was very tight, I know using a rubber mallot and a block of wood to pursuade parts to install
is not the best, but I dont have a large bearing press. Is it common to have such trouble? I used
grease and pulled the crank off to check for gauling.I'am still about 1/8" from hitting the stop,I
reinstalled the bike a have no problem shifting(i.e. chainline) I dont like the small gap between
the crank and the bb stop Thanks

 

I personally would be a bit worried - maybe the FSA is out of spec? Why dontcha contact them
& ask them.