That's me.
This may be possible, however; I have an even better solution.
I've posted a new plug-in on our team website (it may be finicky as we recently had a power outage at school).
First delete the old plug in, which should be either a folder or jar file with the name org.eclipse.cdt.mcc18.toolchain_
version number
Then restart eclipse, and go to help, software updates, find and install....
Choose find a new feature to install, and click next.
Then select new remote site and give the site a name, and enter
http://team254.bcp.org/update_site for the URL and click OK.
Then click next. Click the checkbox, and click next or finish (whichever is active) When it prompts you as to whether you really want to install the plug-in click install.
It will then ask you to restart eclipse. Click yes.
Any projects you create now using the CDT and Managed Make will now have two configurations, one for pre-2006 controllers (i.e. PIC18f8520) and one for the 2006 controller (default.) You will have to recreate any old projects.
This should allow you to compile 2006 code very easily. If you have any urgent questions PM me or send me an email, or else post them in this thread, or a new one if they warrant a new thread.
Glad to see my work is of use!