The reason for the 'Emergency', is because the pid-handling in pBurn is not the best. When pressing the Emergency'-button, all processes related to burning are killed. This includes cdrecord, mkisofs, ffmpeg, .... So in a given situation, it would also kill processes NOT initialized by pBurn, - and this is not good - That's why EMERGENCY.
For the record:
The pBurn helpfile (usr/share/doc/pburn.html) is missing in Porteus. This leads to missing information in the Burn-options window. At first-run, pBurn generates these information variables based on chapters in the helpfile.

At the moment, I am not a Porteus user, but I am easy to reach in the Puppylinux forum.
Sigmund