Accelerator options- 64 and 32 bit differences- why?

[swdw]

I noticed 2 differences between the 32 bit and 64 bit versions of 3.4f by running them on the same machine. Video card is a ATi x1950 pro, and a AMD 3800+ x2 AM2

These differences were while booting sabayon linux w/ no additional boot options
1. XGL and AIGLX appeared as an option with the 32 bit version, but not the 64 bit version, XGL was the only option besides no acceleration. Since this was on the same computer with the same video card- why?

2. 32 bit version correctly picked a resolution and refresh rate. booted into sabayon with no problem. 64 bit version over ranged the monitor frequency

So- it looks like there is a difference between the video program/hardware detection between the 2 releases.