From: "Scott Quinn" <compoobah at valleyimplants.com> It's not what I thought it was- looks like the tape "emulsion" is fine. The looping only seems to happen when the tape gets to the end and is ready to rewind. Listening to the tape, it sounds almost like there's some slack or slippage, but the cartridge seems tight when I look at it (take it apart, poke and prod, etc. The tapes that I'm having problems with (both trapped loops binding the tape and plain read errors) are noticeably noisier than trouble-free cartridges. I'm now wondering about streched band or lubrication issues (they have a much duller surface than newer DC600/DC6150s).