Of COURSE that trick wouldn't work on all renderers. Fall back to something for now, hopefully figure out a better way to do this later. If we have to, we can use vertical line and horizontal line textures for vertical and horizontal lines, and then create custom textures for diagonal lines and software render those. It's terrible, but at least it would be pixel perfect.

Title SDL 1.2.8
Version 1
Description SDL Library for Mac OS X (http://www.libsdl.org)
DefaultLocation /Library/Frameworks
Diskname (null)
DeleteWarning 
NeedsAuthorization NO
DisableStop NO
UseUserMask NO
Application NO
Relocatable YES
Required NO
InstallOnly NO
RequiresReboot NO
InstallFat NO