I probably should add that I'm using SSRS 2008 (not R2). I did as you suggested and the image is embedded in the table and the table is linked to the dataset. It still says under Image Properties\Visibility\Show or Hide based on an expression\fx\Fields\ "Report item not linked to a dataset." However, I went back and removed the first() and just typed in whatever field.value I wanted and it did not return an error when I previewed. I suppose it's just the expression builder (fx) that thinks the image isn't linked to a dataset.

Thanks for your help!