the output file contains one huge line of

\x{4445}\x{3035}\x{533b}\x{676f}\x{203b}\x{2e34}\x{4e37}\x{6475}\x{736f}\x{203b}\x{6f43}

Seriously, an "od -c" of the output file shows this:

0000000    \   x   {   7   6   4   5   }   \   x   {   6   e   6   5  
+ }
0000020    \   x   {   6   f   7   4   }   \   x   {   4   2   2   0  
+ }
0000040    \   x   {   7   1   7   5   }   \   x   {   6   5   7   5  
+ }
0000060    \   x   {   2   0   3   b   }   \   x   {   5   f   5   2  
+ }
0000100    \   x   {   7   5   5   4   }   \   x   {   6   2   7   2  
+ }
[download]

I actually got my hands on a WinXP machine running ActivePerl and ran the script with this code on XP, and got the above output.

Horrible thing is (for my friend) when I run my original script on XP, it works like I expect - NOT producing the \x00 bytes! I don't understand this, and I can't replicate it, and I can't visit him (10 time zones away) to see WTF is going on.