<p>I'm currently developing a PHP application that's using an Access database as a backend. Not by choice you understand... the database is what the client used originally and using it is part of the requirements.<br><br>
One of the problems with this database is that the column names have the most insane naming convention you could possibly imagine. Uppercase, lowercase, underscores, spaces and the plain insane. For example the column "gender" holds a date. And so does column "User2". There's a lot more but you get the idea.<br><br>
Faced with this I decided to create an array to map the database columns to PHP variables so we can isolate the code from the madness. However my colleague believes that I'm over-complicating things and we should use the database's column names for the corresponding PHP variables so we don't need to go through the mapping array to find what goes where.<br><br>
So my question is this... am I doing the right thing or am I complicating things?</p>

Absolutely you are on the right track.  If you don't abstract away the madness you will eventually succumb to the madness yourself.
Your colleague has a valid point though, so I suggest you also code an easy way to determine the data to column mapping in PHP.
This isn't about keeping it simple, it's about retrofitting a solid foundation to build upon.
The thing that would worry me is that this kind of random design often hides certain business rules, things like "...if the gender is a date then they must have purchased a widget at some point therefore they can't be allowed to fribbish the lubdub... " - crazy I know but more common than it should be.