First things first, you are using the terms 64GB and 32GB and they should be 64 Bit and 32 Bit.

As for the install of 2006 on a 64 Bit machine, is because it is a 16 Bit program and they (16 Bit Programs) can NOT be installed on a 64 bit machine.

Were you even able to install FTM 2006 on your 64 bit machine, or did you get a error message (at the time of installing) that it cannot be installed when trying to install it?