Problems with Javascript/CSS minification/gzip

Hi all,
we have a problem when we activate the plugin JCH_Optimize [for Joomla! 1.5.x].
As you can see in the figure, when we enable the option "Combine JavaScript Files" to Yes, a lot of Javascript errors are present.
All errors are related to Template or to some Gavick modules.
If we switch off this option, no errors are present.
As you can understand, CSS and Javascript minification is an important issue in order to improve performance.
How we can solve problems? Do you have alternatives?
This is very important for us.
Thanks in advance.
Alessandro

Apparently the mootools library is not loaded properly causing those issues. Can you PM me your backend access then I can take a check?