I went over the bike twice over to ensure everything is tighten properly and the basic sanity check was to bounce the bike to make sure nothing was rattling and I must say it is very refreshing to have a bike that is mechanically sound again:
I didn't mean that you might have left it too loose, more that the bolts might have been used to correct any slight bend or misalignment in the installation.
Make sure that the fender isn't under stress when you tighten everything up as well, this can make a big difference in the lifespan.