|BUG: Uninstall of PER-USER Installed MSI Fails with a 1309 Error|
Windows Installer can't uninstall files from a directory which the local system account hasn't got write permissions to! You will find a "1309" error message in a verbose log.
Note that Windows Installer can install there, just not uninstall. Lets see how long it takes MS to fix this, a google shows this is not an uncommon problem (note that I'm not holding by breath).