8. PRODUCT WARRANTIES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Product Warranties Details
Balance at the beginning of the period	$ 226	$ 115	$ 222	$ 91
Accruals for warranties issued during the period	62	120	154	250
Settlement made during the period (in cash or in kind)	(80)	(61)	(168)	(167)
Balance at the end of the period	$ 208	$ 174	$ 208	$ 174