Unable to install outlook conncetor with roaming profile + folder redirection

I am trying to install the outlook connector on my Vista SP2 laptop at work. I have administrator rights, and my roaming user profile is set up using folder redirection (http://technet.microsoft.com/en-us/library/cc732275(WS.10).aspx). I get this error message when I try and install:
Failed to open the XML file \\AMSDC1is001C\<myusername>$\Cached\AppData(Roaming)\Soocial\Outlook\Settings.xml , system error: -2147024786

the log file contains this:
<truncated>
Property(S): ProductToBeRegistered = 1
Action ended 14:24:43: ExecuteAction. Return value 3.
Action 14:24:43: FatalError.
Action start 14:24:43: FatalError.
Action 14:24:43: FatalError. Dialog created
Action ended 14:24:44: FatalError. Return value 2.
Action ended 14:24:44: INSTALL. Return value 3.
Property(C): DiskPrompt = [ProductName] Installation [1]
<truncated>
=== Logging stopped: 24/06/2009 14:24:44 ===
MSI (c) (0C:74) [14:24:44:987]: Product: Soocial -- Installation failed.

MSI (c) (0C:74) [14:24:44:989]: Windows Installer installed the product. Product Name: Soocial. Product Version: 0.9.86. Product Language: 1033. Installation success or error status: 1603.
</truncated></truncated></myusername>