[Typo3] Extension install problem

[David Cake]

	Extensions do not seem to install. I have no idea why. I 
attempt to install, I get no real error message - it just reports 
that the extension is not installed.
	I get "A difference between the originally installed version 
and the current was detected!" but I don't think this is the problem? 
Under naming errors it says [exception] but no other information.
	I am running on Debian stable.
	Any ideas?
	I am sure it is not a mysql privileges problem. Its possible 
its a unix permissions problem? But I do not think it is -  the 
typo3conf directory (including localconf.php) is writable by the 
apache user.
	What else should I be looking at?
	Regards
		David