Driver Packaging Version 8.552-081028a-070229C-ATI
Catalyst® Version 08.11
Provider ATI Technologies Inc.
2D Driver Version 7.01.01.838
2D Driver File Path /REGISTRY/MACHINE/SYSTEM/ControlSet001/Control/Class/{4D36E968-E325-11CE-BFC1-08002BE10318}/0000
Direct3D Version 7.14.10.0621
OpenGL Version 6.14.10.8201
Catalyst® Control Center Version 2008.1028.2134.36851
As far as I know, in glsl 1.2 you have to use direct array indexing (ie, put a constant value as array index). Sometimes use a variable as an array index would compile if the compiler can unroll the loop, otherwise it won’t.
I don’t know if in glsl 1.3 it is still the case and of your card support it.
On nvidia cards, this works because the compiler choose a special profile that allows indirect indexing.