Hi,

I have a system setup fairly similiar to yours:

1.8 Ghz AMD Athlon XP 2500+
ATi Radeon 9600
...and a gig of RAM.

I was also experiencing the same problem that you had: my images planes were incredibly slow. I'd tried to fix this problem in the past, but to no avail. When I read your post I was really hopeful, so I did what do posted; I went to the display settings and turned hardware acceleration off. I opened up maya, and noticed that something was off, but I paid no attention to it. I loaded an image plane, and it was actually usable this time around...

...but, alas, I've turned hardware acceleration back on. The image plane shows up fine in the orthographic views, but represents itself as a solid black plane in my 3D view. Not only this, but camera names don't work in my orthographic views (this is what I noticed when I started Maya), and suddenly I can't use "High Quality Rendering" or "X-Ray" -- these features are now supposedly unsupported by my card...

Not having workable image planes, isn't the biggest disaster, but it would definitely be nice. I just use textured planes for reference images now -- it's not great, but it gets the job done...

I appreciate your post, though...