Am I going to owe an underpayment penalty?

I just finished doing my taxes, and the software I use says I might owe an underpayment penalty. It was something small, like $25. The reason it flagged this is because I get stock dividends and interest throughout the year that I don't pay taxes on until the end of the year. This interest and the dividends are reinvested in whatever investment they come from. So my first question is will the IRS actually charge me for this type of thing, and my second is how can I avoid it? Can the places I invest things with withhold taxes if I request that? I'd certainly rather them do that than have to pay a penalty...I've just never had to do this before.