When you upload a wallet.dat file to a new qt install do you also keep your old wallet addresses in thenew install? Im curious as to how I protect my signing addresses when changing computers.
If you replace the new wallet.dat with the old wallet.dat, then you will retain the old wallet addresses, but you will lose the new wallet addresses.
If you have a need to keep both the new and old addresses for some reason, then you'll need to use the dumpprivkey and importprivkey commands in the "Console" window.