It seems though, that not just any cURL will do. I have installed JMonitoring on 8 different sites, and all those where the webhost is running cURL v. 7.15.5, just don't work. I've described the issue on http://joomlacode.org/gf/project/jmonitoring/forum/?action=ForumBrowse&forum_id=12855&_forum_action=ForumMessageBrowse&thread_id=14667 and hope to solve it at some point.

But in general a very good extension and i really hope it will expand over time!

Good work!