I took the build.prop from H and put it in G, but I still can't download.
Don't know what else could be the problem. Maybe a wipe to reset the market data.
I doubt that its just a messed up file or something like that for it to happen to multiple phones with the g build on them at the same time and on the day the pre-release 1.5 sdk is released. coincidence.....i think not.
now that i think about it android community had a post aout froogloid(or w/e its called) and how they saw that someone was using the magic in the U.S. it could of been a g1 running the g build port and downloading their program. what ever lets them see what kind of device downloaded their app could also be the way google might be blocking the g builds. using this theory then the h build must show up as an unkown device since its a prototype build for a chinese/taiwanese phone or it shows up as the g1 and the only way to block it would be to shut everybody out.