XAMPP for Mac version 0.3 is very old: June 29 2005. The first version of XAMPP for Mac I used, was XAMPP for Mac v0.5, so I don't know anything about versions before.
Or did you check the version of the control panel? The version of the control panel is not always equal to the version of XAMPP itself. In the XAMPP for Mac 0.7.x-series the version of the control panel was 0.3.
To check the version of XAMPP:
1. Start XAMPP.
2. Go to http://localhost/xampp
in your browser. You should see the XAMPP-version now.
If you've really XAMPP v0.3, I recommend you to install a newer XAMPP version. If you've no PHP-applications that are only compatible with PHP 4 and not with PHP 5, then you could at best install XAMPP for Mac v1.0.1, which has PHP 5.2.9. XAMPP for Mac 1.7.2a is the newest version available, but I don't know if Wordpress is already compatible with PHP 5.3.
If you use PHP-applications that are only compatible with PHP 4, then you could install XAMPP for Mac v0.7.4, this is the latest XAMPP version with PHP 4.
As for Wordpress, I can't help you with that, since I never used it. But maybe an other forum member can help you if it is a Wordpress issue.