April 1 2015 - 3:46 pm
Latest Security Update Affects EPPC Protocol
Apple's latest Security Update (2015-002) apparently affects the EPPC protocol on OS X 10.8 and 10.9 and prevents Remote Apple Events from being sent/received correctly. Topher Kessler has more at MacIssues and there is this thread at MacScripter.
UPDATE: This issue was fixed with Security Update 2015-004 for 10.9 and 10.8.