In my experience this is true. A long while back, at work we had a client that kept sending us boxes of blank HD 3.5 disks for use on PCs. We never needed them (sent all the data va modem), and some at my office kept taking them and formatting them as 800k in our Macs (SE's and Pluses at the time). None of them lasted more than a few weeks and a few dozen read/writes. They generated read/write errors fairly quickly, and always ended up loosing data. Some wouldn't even take a format. I can't imagine them being much better for a 400k disk (which was really a single sided 800k disk as far as Apple was concerned... but don't be fooled into thinking a 400k disk is safe to format as 800k... I have many many disks that went bad doing that as well... I can only assume that only one side of the media was tested as good in manufacturing). I had even worse experiences with punching a hole in a DD 3.5 disk and formatting for 1.44 (I even have one of those hole punchers sold for just this purpose). I think of the bunch that I tried (I think it was a pack of 25), only something like 5 even took the format, and those 5 failed almost on their first use... that was a total disaster of an experiment (I bought the puncher and a pack of disks specifically to avoid the higher HD cost... it was after this failure that I looked up info on the disks and learned WHY this wouldn't work, then I was amazed at the fact that a company sold a punch tool for it... but like PT Barnum says...) -chris <http://www.mythtech.net>