It may help to give an example:
On my last re-install (which was done to correct a kludge partitioning scheme I had used as a stopgap when / partition started to run out of space), I retained my /home partition. During post-installation of the "new" OS (still 2012.08, which, at the time was a release behind), I created the root user account, and then created my normal user with the same name as I had been using before. This meant that this particular "normal" user acquired the User ID 500, which was its User ID before the re-installation.
It's been my experience that, if a user's account is recreated with the same user name and user ID as before, everything just works. If the user name or user ID is different, you get into having to import data from an old account to the new one and things tend to break if you're not careful.
This is why I said earlier that the order of creation of these accounts is important - accounts acquire user IDs in sequence starting by default with 500.
You might check and see what user ID your account is using. With only one user, it should be 500 and, as long as the user name is the same, all should be well. What is not working for you?
Jot back and let's see if we can work this.