The tax rate on that one transaction is not that high. You can't look at the tax due in that manner. What you did was increase your Adjusted Gross Income. That can cause all sorts of other changes in your return including causing some of your Social Security to become taxable.
Because you are using the Desktop version, it's easy to double check what's happening. Simply print your 1040 after entering the 1099-R info, then delete it and print the 1040 again. Lay then down next to each other to see what amounts really changed in your return.
It would save you a little time if you print this return that's completed, then save it under a different name. Then you can delete the pension income from the new file and print the 1040 and you'll still have your completed return under the old name.
