Thanks for your question.
Yes, if you have a defined benefit plan, you are considered to be covered under a retirement plan at work. Your W-2 should have the retirement plan box checked.
The contribution limit for traditional IRA is $5,000 in 2009. If you were age 50 or older by the end of 2009, the limit is $6,000 including the $1,000 catch up contribution.
Since you are covered by a retirement plan at work, for 2009, if your modified adjusted gross income (MAGI) is over the following amounts, then your tax-deductible contribution to a traditional IRA is subject to a phased-out limit:
For more information, please see IRS 2009 Publication 590
Hope this helps,