Problems with unloading capi module

[Vogi]

Hi there,

i just recognized, that i get an error when the system shuts down:

ERROR: Module capi is in use

So tried it manually:
rmod capi

but the Messsage is still the same: ERROR: Module capi is in use

Is this a problem: When the system is running, i can work with my ISDN card (Fritz PCI) normally.
But unloading the module does not work. This error is new to me, but i cannot tell, when it appeared the first time.
My system is up to date. So did anything change and do I have to change some configs?

Thanks,
Vogi