I just received a really nice 1993 Kenwwod KX-7030 3 Head 3 Motor Dual capstan cassette deck off ebay,it works perfect exept whenever i playback or record over a tape that was made on one of my other decks it ruins the tape by putting diagnal creases in the tape but whenever i use a fresh virgin blank (XLII-S or SA-X) it's fine,records fine and plays back fine.Could one of my other decks have damaged the other tapes some how?When i look at the surface of the tape i don't see anything but when i hit play i can here the deck nibbling on it and when i pop it right out i see the diagnal crease.It's strange to me that it only does this with tapes that where recorded on other decks but fresh virgin tapes work fine..Does anybody know what can be happening here?Thanks for any help or advice anyone can give me..Oh and yes the deck has been completely cleaned..Thanks so much,Keith H.