Hi,
I don’t think I can run requests in parallel, but you can always switch back to the original plugin or modify the version I sent you (the code in in mappress_query.php).
Buffering was just a guess – I was trying to think of something that might be uniquely configured on that server, or might be mangled by another plugin. Did that seem to fix the problem?
What do the PHP and Apache logs show during an error?