From that code snippet I'd guess that they're both being rendered but one is just covering up the other. Multiple gradients don't really make sense unless you (a) use rgba colors so the top one is semi-transparent (only partially supported in IE < 9), or (b) you use background-size and non-repeating bg layers (not at all supported in IE < 9).

I tried using RGBA values to no avail. I'm trying to fake an inset box shadow, since PIE doesn't render that.

on a related note, getting anywhere with the whole inset border radius issue? I just read through the comments and was curious if anything new came up in the past couple months.