[Morrus]

Here's what he said:

In php.ini I changed the line
zlib.output_compression = On
to
zlib.output_compression = Off

Earlier when I was in there I had changed it too on (it was off). In the past I have found better performance from php websites having it on.
If the website does zlib compression as well it can cause problems. Most sites check to see if php has it on to avoid the problem, but it seems the link software doesn't.

So that was the (second) issue. The first, as you surmised was the allow_url_fopen. Don't know if that's any help to you (or anyone else who might end up in this situation).