No luminance alpha compression on 4500/5500

[solofx]

I cannot get luminance alpha textures to compress on a Quadro FX 4500 or 5500.

I'm calling glTexImage2D with internal format GL_COMPRESSED_LUMINANCE_ALPHA_ARB and format GL_LUMINANCE_ALPHA. This worked on the 4500s prior to installing driver 1.0-9755.

Thanks!

[netllama]

Please detail how this problem can be reproduced, including a test app.