I'm glad that you got everything working, John. Let me just answer a few of the questions here for others.
I did find something which referred to adding to the Resource table using one of the ASP.NET Samples but I couldn't find the sample they referred to on my system, there are plenty of other samples but not that one.
This is the Resource Administration sample, it is in the "AdminSample" folder. Where that gets installed on your system varies depending on whether you are running Windows Vista or Windows XP, the samples are rooted in the following folders:
Windows Vista: C:\Users\Public\Documents
Windows XP: %USERPROFILE%\My Documents (where %USER PROFILE% is something like C:\Documents and Settings\LOGON_NAME)
From here the C# sample can be found in Infragistics\NetAdvantage for .NET 2008 Vol. 3 CLR 2.0\Samples\ASP.NET\WebFeatureBrowser\WebSchedule\AdminSample and the VB sample can be found in Infragistics\NetAdvantage for .NET 2008 Vol. 3 CLR 2.0\Samples\ASP.NET\WebFeatureBrowserVB\WebSchedule\AdminSample.
I'm not sure but it might have something to do with not setting the Resource on the WebScheduleInfo properly. There appears to be nothing in the documentation that I found which explains how to use or do this.
See the "Creating a Logon Dialog Box for Your WebSchedule Application" walkthrough for information on setting the ActiveResourceName property on the WebScheduleInfo control. I'm afraid most of the other examples in the help avoid setting an Active Resource so that they can focus on just the code necessary for their particular topic. When no ActiveResourceName is set, the Unassigned Resource (-999) is used. Yes, when you do this you'll need rows corresponding to each named user in your Resources table.
I'm not sure the flash and quick close of the Edit Appointment form you mention would be caused by the Resource not being set, because there is always the Unassigned Resource. If anyone has this problem, they may wish to consult the documentation for "Including WebSchedule Dialog Forms in your C# Web Site" (or VB.NET version of same).