[MC-11033] Item count / numbers randomly flickering in item bar, inventory, workbench

Since one of the last snapshots item count is randomly flickering in item bar. It switches between different numbers randomly. It happens with all 3 smooth lighting settings (off, minimum, maximum).

It happens since snapshot 13w09a.
It does NOT appear in an earlier snapshot or in version 1.4.7
It still happens in snapshot 13w10a.
I don't use mods / Optifine.

Affected Graphic cards:

OpenGL: AMD Radeon HD 6520G GL version 4.2.11554 Compatibility Profile Context, ATI Technologies Inc.
OpenGL: AMD Radeon HD 6800 Series GL version 4.2.11631 Compatibility Profile Context, ATI Technologies Inc.
OpenGL: ATI Radeon HD 4300/4500 Series GL version 3.3.11566 Compatibility Profile Context, ATI Technologies Inc.
OpenGL: AMD Radeon HD 6300M Series GL version 4.2.11318 Compatibility Profile Context, ATI Technologies Inc.
OpenGL: ATI Radeon HD 4800 Series GL version 3.3.11653 Compatibility Profile Context, ATI Technologies Inc.

Not affected Graphic cards (Catalyst 13.1):

OpenGL: AMD Radeon HD 6700 Series GL version 4.2.12002 Compatibility Profile Context 9.12.0.0, ATI Technologies Inc.
OpenGL: AMD Radeon HD 7700 Series GL version 4.2.12002 Compatibility Profile Context 9.12.0.0, ATI Technologies Inc.