Hmmm... You mean you opened a paragraph and didn't close it within the same table cell? That could definitely play havoc with spacing.
When you validate the HTML, doesn't it nag at you about using a style sheet? Mine did. (Along with saying something like "I have no idea what this is, so let's try 4.01 Transitional." That was, ahem, some years ago. Header? DTD? Wha dat?)