CPU overload

hi all,

I am developing an external that talk with an IIDC compliant camera through the libdc1394 library.
I am experiencing some strange CPU overload.
As soon as I start the transmission – i.e. I call the dc1394_video_set_transmission(x->camera, DC1394_ON) function that ask the camera to start the data transmission over the firewire bus – the MaxMSP Runtime thread reaches 150% of CPUs.
I am posting this here because the code works well when it is compiled alone, without the Max SDK.

Does anyone have an idea on how to get this to work ?

thanks

antoine