Installed service packs in this order:
SP1 RU6 - 14.1.355.002
SP2 - 14.2.147.5
SP2 RU3 - 14.2.309.2
After installing RU3, the Exchange MMC and PowerShell get-exchangeserver both show the build to be 14.2.247.5.
The ExchangeSetup.log DOES NOT SHOW 309.2 being installed. It shows build 247.5 installed but not 309.2.
However, the Application Event Log has an entry (id 1036) with this description:
Windows Installer installed an update. Product Name: Microsoft Exchange Server. Product Version: 14.2.247.5. Product Language: 1033. Manufacturer: Microsoft Corporation. Update Name: Update Rollup 3 for Exchange Server 2010 Service Pack 2 (KB2685289)
14.2.309.2. Installation success or error status: 0.
Any ideas? Did RU3 install?