Posted: 24/06/2013 at 17:30
Any chance that you pruned it back just too hard last year? If you pruned out non-flowering wood last year, which should have flowered this, then no flowers. The resulting 'new wood' will not have had the chance to ripen fully last summer & thus flower this, but should do again next year.
Sometimes though shrubs do 'have a yr off' for no reason IME. J.