A button inside a tables render differently in different browsers Opera and FF: behave the same.
Created attachment 16395 [details] A button inside a tables render differently in different browsers
A size of the button element depends on default browser style sheet. The default style sheet can be easily overwritten by author using height, width etc. So the bug is minor, cosmetic evangelism bug.
The reported site isn't available for public any more. I close the bug report.