I also had done the 14.0 update earlier this summer, so my version numbers were the same as above. When I went to install the new 14.5 update, it also said, "
This version of the update is already installed. Continue the update?" Oddly enough, the software version mentioned on screen with that question was the new software and a slightly different version than what I already had. I proceeded with the update (the "quick" version

), and these were the resulting changes:
SW ver.
OLD ON.USA.S5W_M.V004.001.200324
NEW ON.USA.S5W_M.V004.001.
200702
Firmware ver.
OLD ON.USA.301.200316.MICOM.D
NEW ON.USA.301.200316.MICOM.D
Nav App ver.
OLD STD5W.NAM.KMC.200319.168fa330
NEW STD5W.NAM.KMC.200319.168fa330
Map ver.
OLD NAM.13.41.42.660.202
NEW NAM.13.
47.44.680.201
As noted in the changelog, this version contains solely map updates, so it makes sense that most of it is identical to the prior release.