hello
in guid
go to disk util and make the partition to 7 in fat 32
insert u media install for 7 and boot
dont mess with the partition scheme, u have done in mac os x with disk util
only format the fat 32 in ntfs and install
if 7 mess u boot with chameleon, simple reinstall chameleon, the chameleon loader take care of the dual boot
and done
good hack