Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Statement [Abstract]
Net sales	$ 47,632	$ 54,274	$ 143,310	$ 152,324
Cost of sales (exclusive of amortization of purchased and core technology shown separately below)	21,884	24,877	66,302	70,909
Amortization of purchased and core technology	444	642	1,491	2,343
Gross profit	25,304	28,755	75,517	79,072
Operating expenses:
Sales and marketing	9,920	10,134	30,359	29,464
Research and development	7,779	7,860	23,764	23,517
General and administrative	4,560	4,597	13,808	13,670
Restructuring	963	0	1,259	(70)
Total operating expenses	23,222	22,591	69,190	66,581
Operating income	2,082	6,164	6,327	12,491
Other (expense) income, net:
Interest income	71	61	217	187
Interest expense	0	(26)	(15)	(79)
Other (expense) income	(192)	(378)	(37)	(613)
Total other (expense) income, net	(121)	(343)	165	(505)
Income before income taxes	1,961	5,821	6,492	11,986
Income tax (benefit) provision	(346)	2,206	1,339	3,816
Net income	$ 2,307	$ 3,615	$ 5,153	$ 8,170
Net income per common share:
Basic	$ 0.09	$ 0.14	$ 0.20	$ 0.32
Diluted	$ 0.09	$ 0.14	$ 0.20	$ 0.32
Weighted average common shares:
Basic	25,770	25,369	25,705	25,236
Diluted	26,043	25,879	26,138	25,687