Are other interrupts working OK? If not, here are a couple of suggestions:
(a) Have you cleared the MASKALL bit in the IMRL register?
MCF_INTC0_IMRL &= ~MCF_INTC_IMRL_MASKALL;
(b) Have you dropped the interrupt fence in the processor's main status register (SR)? The processor boots with the value 0x2700 in the SR, which means that the fence is 7 and all interrupts are masked. To set the fence to 0, try something like
asm_set_ipl(0);
Hope this helps
Simon