Coming quick on the heels of the first public release of FotoStation 4.5 late last month, Build 116 appears to fix a problem with the trial version not functioning on machines that previously had v4.0 installed. It also appears to extend the trial period to 30 days, up from 15.
The actual changes in Build 116 for Mac and Windows are not specified, however, on the FotoStation web site. Only the application itself changes in Build 116; installing it involves replacing the application from the Build 112 folder with the Build 116 version. In other words, as I write this it appears that it's necessary to download and install Build 112 of the trial or registered version, then update to Build 116 from there.