I have a simple table (1 row, 4 columns).
Three of the images have identical dimensions (108 x 200 pixels). After placing them each into a cell of the table, the middle image is not aligned with the other two. Instead, it is higher in the cell.
I looked at source code, and everything appears to be identical. Also, every image has the default setting for alignment (center, middle).
How can I fix this?
It looks like you are looking in the design view. this is not particularly a good guidance because there is no guarantee that your page will look exactly like it in the browsers. You need to preview the page to see it properly. As Nancy has already said, you need to post your code for her to advice you further.