Keeping a fixed drive letter for a mobile pone

For over a year, I have been connecting my Android phone to my laptop with USB so that I can sync certain files. The software I use needs to be told where to sync to, and until recently this was always drive I when the phone was connected. Recently, Windows has been allocating drive letter G to the phone when it is connected, and the sync software can't find it.

I have been into the disk management console and allocated the letter I to this device but it returns to G whenever I have disconnected and reconnected it, whether there has been a reboot or not. Does anybody have an idea how I can make this drive allocation stick? Everything I have found so far either says to do what I have done, or is not really relevant to this issue.

Windows 7 ultiimate, Android Gingerbread, GoodSync for syncing files.