From what I have seen since I first noticed it, this issue is very wide spread and well doccumented, more so for the NA and CN maps. I am guessing that, those who only updated whole, maps, not just incremental updates such as, the .20,30,40 etc and just updat 2013, 2014, 2015, may not have this issue of the renamed file. Or people just have not realised that the DEM map option in my maps is missing becuase of a reaniming issue and thinking that it is by design as the device DEM mapping is working as it should.
i will be able to confirm this when I rename the file, but not for a few weeks when I won't be needing my device. Unless anyone else is able to play with their D2249750A.IMG (or similar) and the gmapdem.img file?