I sometimes wondered why Rock Falcon always had a noIcon texture in my viewport, even though if I did a render region, I could see the texture was really there.
I assumed it was something about the software on my system, because Manny didn’t have the same problem even though he has the exact same hardware.

Then I read this post from Luc-Eric on the mailing list:

I discovered a bug in the standard jpeg library that causes a problem
with some formats of jpeg — probably progressive.
It uses a temp file to decompress them and in Windows that ends up
being a temp file in the root of the drive. If you’re under Vista or
some account with limited privileges that prevent writing to the root
of the drive, the jpegs won’t load.
via JPG Baseline / Progressive – Google Groups.

I did a quick check with Process Monitor, and I saw that Softimage was indeed trying to create a file in my C:\ driver, and getting ACCESS DENIED.
I checked Manny’s machine, and he can write to the C:\ drive because he has UAC disabled.