The withholding feature in Q2007 Tax Planner is pretty erratic and it's estimates of taxes due should be verified with a hand calculator. There are some program bugs that could lead you astray. The problems I've seem to stem from the withholding calculations.
The withhold detail screen allows selection of 1 Estimate based on YTD daily average or 2 Use Per Period Amount.
Using option 1 works correctly if you don't have any extra pay events during the year. But just a little extra early in the year causes Quicken to grossly over-estimate total withholding for the year.
Program bug - Quicken Tax Planner offers a spot to enter and adjustment. But as you move between windows, the adjustment is lost. The adjustment value still appears in the spot you entered it, but it is not applied to the value shown in Tax Planner Summary. Switching between 1 and 2 brings things back into agreement.
Program bug - Using option 2 is a non-starter. I doesn't pull in any of the future withhold payments and you end up with a very large underpayment value. This value is big enough that you will know something is wrong.
Anyone know of plans to improve this feature in future Quicken releases?