So you took the APK file and put it on your SD card, then used ASTRO ?? to attempt to install it?
I thinik then your only option is to do it via that link I posted, that walks you through using the android sdk to back door the installation.
I had a simialr issue, where I rooted my phone and updated the GL drivers. the ROM I put on had 3d Gallery, but the new GL drivers didn't work with it. So I plopped on 2d gallery, no issue. Did the exact same process to a friends phone and 2d gallery won't install on his. (I just reflashed his phone with an updated rom that had 3d replaced with 2d gallery)
Good luck with the sdk, let us know how you fare.