I just setup Moodle 1.8 (that version is about 6 years old but some older sites still use it). There were no problems as the .zip file is tiny compared to version 2.2. Needless to say, there must be a lot of new functionality added over the years. I am going to explore using version 1.9 once I resolve my DNS issues on my other account. A lot of issues are likely security related. I note that it is July 2010 version 2.0 was first released. So, 1.9 is not really a dinosaur yet.
One small problem I had was that I couldn't log in as moodle admin once the installation completed - that problem was solved way back in 2008 on this forum manually editing the database password string. I wrote down the details in case it matters.
Anybody running Moodle 1.9?? My interest is ESL specifically audio related modules for speaking, listening and pronunciation.