As maroon said above, it's best to always group each condition in its own parenthesis.

Code:
Do:
if (condition) || (condition) then stuff
if ((condition) || (condition)) then stuff

Avoid:
if (condition || condition) then stuff

Addition of { } to make it more readable or support multiple lines or piped commands.

Well. At least I won lunch.
Good philosophy, see good in bad, I like!