DT-INTS and SSP1_INT

I'm able to use the following interrupts from DT-INTS:

1. RX1_INT
2. RX2_INT
3. TX1_INT
4. TX2_INT
5. TMR1_INT
6. TMR0_INT

When I try to use SSP1_INT, the program hangs waiting for the code to execute in the MSSP1 interrupt. I can remove the interrupt and use a GOSUB to execute the MSSP1 module but can't figure out why using the interrupt isn't working. I can confirm that the code goes past the

@ INT_ENABLE SSP1_INT

but it never goes into the SSP1 interrupt. Any thoughts?