Eventually there will probably be an rpm of Xsnow version 1.42, which is available on the Xsnow author's Website. When that occurs, you'll want to upgrade your existing Xsnow installation. If you were to use rpm -ivh --force, it would appear to work, but rpm's internal database would list both versions as being installed. Instead, you should use rpm -U to upgrade your installation:

# rpm -Uvh xsnow-1.42-1.i386.rpm
xsnow                       ##################################################

Here's a little trick: we rarely use rpm -i at all, because rpm -U will simply install an rpm if it doesn't exist yet on the system. This is especially useful if you specify multiple packages on the command-line, where some are currently installed and some are not:

# rpm -Uvh xsnow-1.42-1.i386.rpm xfishtank-2.1tp-1.i386.rpm
xsnow                       ##################################################
xfishtank                   ##################################################