SQL Backup is now compatible with 64-bit versions of SQL Server. It's the same installer for both 32-bit and 64-bit systems (including Itanium and X64 OS's). It will automatically install the correct version of the server components depending on the version of SQL Server.
New keyword MAXTRANSFERSIZE to specify the maximum size of each block of memory to be used when SQL Backup transfers data
To upgrade from version 4.2 (or previous versions) you can follow the link from the Start menu.
Start -> All Programs -> SQL Backup -> Check for updates.