ISDN Interfaces disappear in a in an Askozia Shop's IP+ISDN Appliance.

Hello all. I am having this strange problem: I have an Askozia Shop's IP+ISDN Appliance. I configure it and it is running fine, no trouble at all. However, after several days of using it, I go to the web interface, to the System > Interfaces > ISDN and it says something like "No ISDN Interfaces found", but the interfaces are there and you can use them fine, you can call and receive calls and they work as you configured them.
I then reboot the appliance and after the reboot, you go to the web interface and you can see the interfaces again and modify them as you will. So it seems like the web interface is not able to detect the ISDN cards until you reboot the equipment.
Rebooting is not a problem, but I just want to report this in case you can fix it in the next build.