issue with adding ip core in qysis

I am using Quartus 11.0 and working in DE0 nano board. I am having a state machine in RTL.It was working fine until i add a UART interface in Qysis . After adding UART my state machine is not working properly. UART core is not been used in design of state machine .I just added receive and transmit ports in RTL top level entity for UART ,then issue arises. Resource utilization is below 20 %. what may be the issue ?