a while back I went into an american embassy for some administrative issue, and when I handed them my passport through the glass, they punched a hole in it and I needed to get a new one. the reason was that they felt it was too dogeared. it was an extreme inconveninece to have happen in such a manner, and not when it was planned. I would suggest that if your passport is in bad enough shape that people are questioning you about it, order a new one immidiatly. you should be able to keep the old one, to be able to show the visas, although I am not sure that you can do this with american passports, you might be able to. I would also recomend a passport cover, which I had resisted until this happened to me.