Hi Jonas,
I think that the problem is due to do the permissions given to the folder where these SubVI's are located. Under WinNT 4.0 Terminal Server's user account, Read-Only privileges are maybe given to that folder. Therefore, even if you install the components as an Administrator in NT, all users in Terminal Server mode will not be able to acces the subVI's even though they are present.
To get around this problem, change the privileges for users on the specific folder, where the subVI's are located, to Read-Write. This is just a thought so please let me know if this fixes anything?