Considering the various issues that continue to plague the GMD program that fact the SBX is acting up now is not a good thing:

The Missile Defense Agency conducted a flight test today of the Ground-Based Midcourse Defense System.

A target missile was successfully launched at approximately 3:40 p.m. PST from the U.S. Army’s Reagan Test Site at Kwajalein Atoll in the Republic of the Marshall Islands.  Approximately six minutes later, a Ground-Based Interceptor was successfully launched from Vandenberg Air Force Base, Calif.  Both the target missile and Ground-Based Interceptor performed nominally after launch.  However, the Sea-Based X-band radar did not perform as expected.

Program officials will conduct an extensive investigation to determine the cause of the failure to intercept.  [MDA Website]

The thing people need to keep in mind is that this system is extremely complex and what it is doing is not easy and thus needs testing and with testing you have trial and error.