Don't know about MainMenu, but OnyX works fine for me and its is free too. 
Running  10.6.7. 

Doug

On 17 May 2011, at 12:39, jem cabanes wrote:

> So far I've been using 'Mainmenu' to keep my Mac healthy  --up to v. 1.7.4, afterwards I found it shaky so I went back to 1.7.4. But Leopard systems seem to be less compatible with Mainmenu. Thus, I've been thinking about shifting to MacKeeper, and since they don't offer a real demo, I'd like to take advice from any lister that's using it.
> 
> 
> Many thanks in advance.
> 
> 
> jem c.