Vertical image alignment problem in firefox 1.0pr

I have just started using the grid widget and I've run into a small (I hope) issue. When a row is displayed on the grid that conatins an image the image is positioned almost an entire row below the point it should be. This only occurs if the image is by itself in the column. It is positioned correctly if there is also text (other than a space). Column grid lines are also dropped below the correct row position. Everything works ok in IE 6.

note: I am using the .active-box-image {height 16px;} firefox fix. The images are 16x16px

Other than this annoying problem I'm really impressed, keep up the good work!