i've got a fix for the uncached templates (thanks to Lynne

)
Go in the ACP ---> Plugin & Products ---> Plugin Manager --->
Mass PM Social Group Members - Cache Template (EDIT)
and put the following code at the end ...

this cache the templates ... however there is another trouble in this hack ... when you select to send a PM to the users the 'Community' Link doesn't work ...
PHP Code:
if(THIS_SCRIPT == 'group')
{
$globaltemplates = array_merge($globaltemplates, array(
'editor_clientscript', 'editor_css', 'editor_jsoptions_font', 'editor_jsoptions_size', 'editor_toolbar_on', 'socialgroups_masspm'));
}