Got it working now!! - Interesting solution:-

Remember - the perl script was transferring the file correctly when run from the command line, but when the perl script was invoked from the browser I would get the error:

"501 Protocol scheme 'https' is not supported (Crypt::SSLeay not installed)"

Solution:- add the -T option (taint mode) to the perl script, so first line:

#!/usr/bin/perl -w

became:

#!/usr/bin/perl -wT

Not sure why this works - but it does!

Thanks for your help

Jonathan