Well I've tried this on at least 2 AMD GPUs and get the same error so:
When using a component of a vector in a switch statement, AMD's glsl compiler complains about it being nonscalar. It works fine on Nvidia cards though.
[code]
ivec4 value;
switch( value.x ) // error nonscalar value, adding a int() cast is a temporary fix at least.
{
}
[/code]
Not that big of a bug but still...