Same problem here on C2960X with 15.2(7)E2.
3 switches stacked:
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 54 WS-C2960X-48TD-L 15.2(7)E2 C2960X-UNIVERSALK9-M
2 54 WS-C2960X-48LPS-L 15.2(7)E2 C2960X-UNIVERSALK9-M
3 54 WS-C2960X-48LPS-L 15.2(7)E2 C2960X-UNIVERSALK9-M
Had to disable port-security entirely.