SketchUP Pro 2015 Mac version updates

On our Macs with OS X Yosemite 10.10.1, we keep getting prompted to update; yet, the update is the same version as we already have installed. When we run the update anyway, the version is the same (15.1.104), but when you check for updates again, it says you need to install a new update, which is still 15.1.104. Is this a bug? Never seen this with any other version or on any other platform.

recent release is version 15.2.686 from 12/18/14, download from here.