If you really think the problem is opengl related (which I doubt) you can do an updatedb. Then do a locate libGL to find all libGL related files.
I would remove the libGL.so from the quake3 dir since that one isn't needed.
Why don't you run a timedemo in quake3?
For 1.31 it is possible to run them. Here's a quick howto:
- rename pak6.pk3 from the baseq3 to pak6.zip.
- unzip the zip file to a temp dir
- create a dir baseq3/demos (in the quake3 dir)
- copy the file four.dm66 (from the temp/demos dir) to baseq3/demos
- rename four.dm66 to four.dm67
- rename pak6.zip back to pak6.pk3
- run quake3
- enter in the console "timedemo 1"
- then in the console: "demo four"
- after the demo check your fps