Joomla 1.5 caching is confusing (plugin especially)

[mehdi]

hi,
when I played first time with Joomla 1.5, I thought that caching was straightforward,
basically I just enable it through global configuration.
But ... I realised that there's also a " System - Cache" plugin , disabled by default.
So I thought that in order to get caching work, I got to enable the plugin.
But after studying behavior I realized that using the global setting & " System - Cache" plugin
were two distinct things that work separately.
Enabling the "global setting" , induce cache of modules only.
Enabling "System - Cache" , induce cache of whole page , including modules, and only if user is not connected.
I found this confusing because:
* if you disable caching in "global configuration", this doesn't disabe the "System - Cache" plugin, and pages are still cached.
* why these two caching ? is it even advised to enable the "System - Cache" plugin, since it is relatively hidden and not very documented ? or is it advised to enable both cachings ?

Note:
I also don't like that the "System - Cache" plugin abruptly exit , after retrieving a cached page.
This prevent my Joomla - Coppermine bridge to work properly.
I bypassed the problem , by disabling the plugin only when the bridge is working; but that's not perfect.

[DipDog3]

I also just enabled the cache and I thought that I need to enable both the global settings and the plug-in. That created some really weird behavior that included missing pictures.

I finally just disabled the plug-in and left the global one enabled and everything was back to normal.

[ircmaxell]

Disabling the global caching renders the plugin inoperative (even if it is published). Basically it works like this:

Global Caching caches modules/components/etc
Cache Plugin enables page level caching (on top of the global caching)...

[DipDog3]

Thanks for the info.
The cache plug-in isn't working properly so I will leave it disabled for now.