can bus interrupt problem.

im using a chipkit uno32 with a canbus shield for a ecu display and its working fairly well, but i find that the chipkit has to be powered up first otherwise no data is received it just sits there doing nothing if i disconnect then re connect the interrupt pin it starts working fine. any suggestions?

no ideas?

In fact i get the same problem with the interrupt not working correctly on my uno32, arduino uno and my mega unless the arduino is powered up first the interrupt does not work correctly.