SM's not getting NTP time update

Anyone have a problem with SM’s not getting thier NTP time updated? If so what was the problem and what was the solution?

Sure the time’s not just GMT? I thought that at first on our SMs but they’re all precisely 4 (5? Damn DST…) hours off.

yes i understand the time differnece, but the problem is that 2 AP off one of 900 Sectors are not getting the NTP time update but the rest of them are.

Would interference cause this?