The two files live on the client PC.
On the client machine if you go to start and then run and put in
%appdata%\Mitel\UC
That will take you to the folder that the two live in. If you look at the sipsubscriber file that has all of the information in it.
I find it best to delete or rename this file with UCA closed and then start UCA up and duplicate the problem. When you start UCA up it will re-create a new file that wont have the last umpteen days of logs in it for you to wade through.