Piece of css code messing with ads in my sidebar

[arm0110]

I'm having trouble with some of my ads shrinking and displaying outside the template margin. The ads are 160x600, but according to a troubleshooter I'm working with at the ad agency, there is a piece of code in the original stylesheet that's impacting the ads and causing them to behave as if they are in a 300px by 250px area. The code is:

#sidebar embed, #sidebar object {
width: 300px;
height: 250px;
margin: 0px;
padding: 0px;
}

Is this piece of code necessary? Any ideas on what I can do to fix this problem?

Thanks so much.
Andrea
www.andreasrecipes.com