Slider disappearing past x 640?

[MikePXP]

I'm making a gui mod and i've run into a strange problem.

 

The slider's border image (GUISLDR.MOS) is getting clipped if I move it past x 640

The knob (GUISLDR.BAM) does not get clipped for some reason.

 

This is at 1920x1080.

 

I've started editing a new install and just moved that window (or any window with a slider) past 640 and it happens so I've ruled out anything else I've done up to that point.

 

Any ideas?

 

[MikePXP]

I've looked at another GUI mod and they had the same problem so I'm chalking this up to an engine limitation.