I have a bunch of Windows 8.1 machines on a 2003 domain that we're managing using a 2012 server as a domain controller. I have an OU that contains all the machines and a GPO I've linked to the OU. In the policy, under User Configuration -> Preferences -> Control Panel Settings -> Folder Options I've created various file type associations and set them to "replace" and have checked "Set as default". In the same policy I've also enabled loopback in merge mode, in order to have the same associations apply independently of the logged in user.
After I do a gpupdate /force on a client machine, the file types that previously had no programs associated with them receive default program associations as defined in the GPO, however the file types that had existing associations are not getting their associations replaced. The same is also true if I try to change the default program via GPO for one of the file types that initially had their first program association set via the same GPO. The only result is that the new program association appears as a choice in the "open with" context menu, while the old default association remains intact. I generated a report using modeling on the server and it shows the GPO as "applied" with no errors.
Any pointers as to what could be wrong and how one would go about fixing this? Thanks in advance.