[PyMOL] PyMol graphics problem in Ubuntu 13.10, ATI Radeon HD 4650

Hello all,
I installed ubuntu 13.10 on my PC. It has ATI Radeon HD 4650 graphics card.
When I am trying to load a pdb file in PyMol, It gives following error.
Which drivers do I need to install?





*EE ../../../../../../src/gallium/drivers/r600/r600_state.c:2373
r600_adjust_gprs - ps & vs shader require too many register (109 + 20) for
a combined maximum of 128 EE
../../../../../../src/gallium/drivers/r600/r600_shader.c:1580
r600_shader_from_tgsi - GPR limit exceeded - shader requires 128
registersEE ../../../../../../src/gallium/drivers/r600/r600_shader.c:158
r600_pipe_shader_create - translation from TGSI failed ! EE
../../../../../../src/gallium/drivers/r600/r600_state_common.c:754
r600_shader_select - Failed to build shader variant (type=1) -12EE
../../../../../../src/gallium/drivers/r600/r600_state.c:2373
r600_adjust_gprs - ps & vs shader require too many register (109 + 20) for
a combined maximum of 128 *
Thanks,

Regards,

Hitesh Patel