That setting change was ill-advised anyway. The Windows graphics driver will automatically allocate the (shared) memory necessary; there is absolutely no need (and zero performance advantage!) to doing this manually. All you have done is limited the memory available to other software. If you did this because you are running one of the games that has a bug causing it to refuse to run (because the minimum is set too low), making this kind of change isn't the right answer; get the fix from the game developer.
With regards to why you posted this info, yea, there are a number of issues (BIOS bugs), like this, that have been seen to occur if you change these numbers in the BIOS. Ironically, this may be because they are not testing the impact of changes to these parameters because you really shouldn't be making any. It's bad either way. Hopefully these will be fixed one day soon...