Leaking oil from sump drain bolt?

[Chriskoss]

Hey guys

for some reason my engine is leaking oil from the oil drain sump bolt..

Ive tightened it as far as it can go (without over tightening of course), still leaks gradually

I took it off when I did an oil change ,and applied gasket goo to the threads and the top.. still leaks

Anyone had this problem before, what is the solution? A new bolt?

I read somewhere every time you do an oil change you need to replace the washer or something, not sure?

thanks