I just successfully upgraded from Exchange 2007 v8.2.176.2 to SP3 8.3.83.6. Rebooted the server verified v8.3.83.6 was listed on the server configuration screen and successfully tested functionallity.
I then upgraded to Exchange 2007 SP3 Update Rollup 3-v2 and received a successfull upgrade compleation message. Rebooted the server, but the version listed on the server configuration screen is still v8.3.83.6, when it should be v8.03.0159.002. I tried reinstalling Rollup 3-v2, but it didn't help. I have tested and Exchange seems to be working just fine.
We are using ForeFront Protection and I did disable ForeFront before installing the updates.
I haven't opened the server up to internal users or external mail yet and have a SAN snapshot of the Exchange programs, database and logs (D & L drives), but the OS (C drive) is on direct attached storage and I don't have an image of it.
I figured I would check to see if anyone else has run into this before trying to revert the SAN components back to SP2.