Yup, lost to them too (0-1). Blotted that one out as well.
https://www.11v11.com/teams/brighton-and-hove-albion/tab/opposingTeams/opposition/Leatherhead/
We haven't beaten many non-league teams have we?
And Sudbury Town.
I think that may be it (of teams we have actually played).
Edit: no it isn't. Apparently we've played Bedford Town twice and never beaten them. Before my time though.
https://www.11v11.com/teams/brighton-and-hove-albion/tab/opposingTeams/opposition/Bedford%20Town/