There has been an issue with table border colors in Firefox not displaying correctly for a little while now. The problem is that it is not showing the correct color, or it is showing a black line in the top and left sides of the cells of the table. There has been a work around created for it. Just add this line of code into your css and it should fix the problem,
table, table td { border: solid 1px #eaeaea; /* or whatever color you want, just add the hexadecimal number */ }
Cya
