Operating expenses were $21 million in the fourth quarter of 2011 compared to $18.5 million for the fourth quarter of the prior year. Research and development costs in the fourth quarter of 2011 were $6.8 million compared to $5.6 million in the fourth quarter of 2010. Attributing to this R&D increase was a $1.1 million impairment charge related to a discontinued product and $500,000 related to a discontinued research and development project.
Sales and marketing costs increased to $6.8 million in the fourth quarter of 2011 from $5.9 million in the fourth quarter of the previous year due to an increase in sales commissions associated with the increased sales in 2011.
General and administrative expenses in Q4 of 2011 increased to $5.7 million from $4.9 million in the fourth quarter of last year. This is primarily related to an increase in employee incentive compensation in 2011 versus 2010.
Stock-based compensation expense was $2.3 million in the fourth quarter versus $1.3 million for the comparable period in 2010. In the fourth quarter, we've recorded in the other expense line item $400,000 primarily associated with a facility shutdown in Ohio. In total, all of the aforementioned one-time items had a negative impact of approximately $0.04 per share.Our tax rate for the fourth quarter of 2011 was 30.1% and for the full year our effective tax rate was 33.5%. This compares to a tax rate of 35.3% for the full year of 2010. Net income in the fourth quarter of 2011 was $1 million or $0.03 per diluted share compared to net loss of $400,000 or $0.02 per share for the fourth quarter of 2010. On a non-GAAP basis excluding non-recurring items, amortization of intangibles and stock compensation expense, net income for the fourth quarter of 2011 was $4.9 million or $0.15 per diluted share. This compares to net income of $1.5 million or $0.05 per diluted share for the same period in 2010. Read the rest of this transcript for free on seekingalpha.com