As I've discussed before, ASI won't work unless your clients can get to the file shares created by the ASI server setup. Here's an issue that is difficult to troubleshoot. If you're using Windows XP SP2 the UI will tell you that the images folder is being shared, but when you browse to it you get an access denied. This is a bug in ASI, and also in Windows in my opinion. I'll get the ASI portion fixed; until then, here is the issue and the work-around.
The problem is that the ASI server setup is assuming that you're in a domain. The folder is shared with permissions applied for specific accounts but those accounts don't exist without the domain so you get an access denied when you try to access the folder. The work-around is easy, un-share the folder then share it again.