Horrible: Apache corrupting files?

[Ben Paley]

Hello,

I have Apache 2 running on FreeBSD 6.1-PRERELEASE on a laptop on a small 
office lan. Whenever one of the other machines (mostly Macs) makes a request 
for a certain page on my machine, it is delivered succesfully but the file 
itself is absolutely scrambled beyond recognition into a binary file. 
Subsequent requests rescramble it into a different but equally nonsense 
binary.

I've looked with a binary editor and it really is completely messed up. I can 
restore the file from a good archive copy, but every time the same thing 
happens.

The file was originally created on a mac by Flash (it's a 1.1k html file which 
just embeds a flash movie). Recently I copied it to and from a Solaris box 
via ftp from an Windows NT machine (although it wasn't opened afaik - a long 
story, clearly, which also involves a usb flash drive...).

Anyone have any ideas? The file itself is inconsequential, but the fact of 
such blatant and relentless data corruption is very worrying to me! I don't 
know if it's the file or my system or some combination... I'd really 
appreciate some advice, I've been staring at it for two days and I'm starting 
to bite my nails...

Thanks a lot,
Ben