Mathematics tools

I installed the Algebra filter and it works fine so far. But the image created contains the absolute URL. Example: http://moodle.x.org/.....

I create courses which run from an USB stick and on boot time take the IP adress from a DHCP server. This can be different any time the USB stick boots and therefore the formulas are not portable.

Is there a switch to tell the Algebra filter to create relative URLs?

Thanks
Karl