The forum search at the link above may still be helpful to those that use other browsers that are complient with the opensearch standard.
I just updated the forum search plugin with the new / correct forum URL, that is why it is listed twice at the above link; the old one should be removed within 7 days (once the mozdev folks confirm that the changes are not malicious)
The multi search plugin uses google, so the change to the forum URL is not important (it searches pclinuxos.com, mypclinuxos.com, the mag website, linuxgator, etc..using google). It is not installed with firefox by default in PCLinuxOS (..yet ?)