Income Taxes	6 Months Ended
Mar. 31, 2012
Income Taxes	9. Income Taxes Effective Tax Rate The effective income tax rate was 32.6% and 29.8% during the quarters ended March 31, 2012 and 2011, respectively, and 31.8% and 26.8% during the six months ended March 31, 2012 and 2011, respectively. The provision for income taxes during interim quarterly reporting periods is based on our estimates of the effective tax rates for the respective full fiscal year. The effective tax rate in any quarter can be affected positively or negatively by adjustments that are required to be reported in the specific quarter of resolution. The increase in our effective tax rate year over year was due to the recognition of the 2010 extension of Federal Research and Development credit during fiscal 2011 and the expiration of the Federal Research and Development credit during fiscal 2012. In addition, there was a one-time entity restructuring charge in the first six months of fiscal 2012. The total unrecognized tax benefit for uncertain tax positions at March 31, 2012 and September 30, 2011 is estimated to be approximately $7.6 million and $9.5 million, respectively. We recognize interest expense related to unrecognized tax benefits and penalties as part of the provision for income taxes in our consolidated statements of income. As of March 31, 2012 and September 30, 2011, we have accrued interest of $0.3 million and $0.8 million, respectively, related to the unrecognized tax benefits.

Income Taxes

6 Months Ended

Mar. 31, 2012

9. Income Taxes

Effective Tax Rate

The effective income tax rate was 32.6% and 29.8% during the quarters ended March 31, 2012 and 2011, respectively, and 31.8% and 26.8% during the six months ended March 31, 2012 and 2011, respectively. The provision for income taxes during interim quarterly reporting periods is based on our estimates of the effective tax rates for the respective full fiscal year.

The effective tax rate in any quarter can be affected positively or negatively by adjustments that are required to be reported in the specific quarter of resolution. The increase in our effective tax rate year over year was due to the recognition of the 2010 extension of Federal Research and Development credit during fiscal 2011 and the expiration of the Federal Research and Development credit during fiscal 2012. In addition, there was a one-time entity restructuring charge in the first six months of fiscal 2012.

The total unrecognized tax benefit for uncertain tax positions at March 31, 2012 and September 30, 2011 is estimated to be approximately $7.6 million and $9.5 million, respectively. We recognize interest expense related to unrecognized tax benefits and penalties as part of the provision for income taxes in our consolidated statements of income. As of March 31, 2012 and September 30, 2011, we have accrued interest of $0.3 million and $0.8 million, respectively, related to the unrecognized tax benefits.