If you are saying that you would like to set the mouse tracking speed for all users of the system I do not believe there is a way to do that. Each will have his/her own preference.
If you are saying that when you set your preference and then log out/log in under the same user and unexpectedly find that your preferences are not retained then there should be a fix.
Likely cause ,either:
The the permissions on the preference file are set incorrectly -- This might be fixed in disk utility -- repair permissions. Logout and then login.
The permission file is corrupt. You should move it to the desktop, logout, login and set the permissions. Should stick now. I believe the preference is stored here: