Re: impossible to copy
I get mixed results with Admin Mods. I was able to install the clock module, as a test, but like you I got the "impossible to copy" error with phpfreechat. So anyway it seems this isn't a local problem of your installation. (For what it's worth, phpfreechat is buggy and doesn't work anyway, at least in my testing. I haven't heard of anyone being able to use it.) More checking is needed to track down the cause of these Mods install problems (maybe bad path info at the repository). But actually Admin Mods is just an automated version of what you can do by hand: get the files in the mods repository and put them in the correct directories of your server, so you can do this (get them at http://tikiwiki.svn.sourceforge.net/viewvc/tikiwiki/mods/trunk/) to install them if Admin Mods fails.
-- Gary