Hi Stig, This could be the sort of question best asked in a support forum relating to the program or the plugin. <u>Plugin</u> *What exactly is the plugin: where is it from & plugin's homepage ? * I did find http://djvu-editor-external-version-4-1-0-545.software.informer.com/ ** apparently relating to ''DjVuPro.exe''. **from http://lizardtech.software.informer.com/ Is the software paid for, if so I would expect the software to have some sort of support. <u>"Häradskartan"</u> You have not provided any information about that *Again do they have a support site? * What is the program and how does this use Firefox?