There is a new 5th gear synchro for FDs... I dunno which one you had for your second one... original stock or the new replacement part... Make sure you get the newer one.
I recently replaced my stock 5th with a new one and I replaced the synchro while I was at it just for good measure. The original one is a little more golden in color and the newer one is more of a gold-bronze color. Other than the color, I can't tell them apart.