Ok... I think I may have finally found a fix for this, although I can't exactly replicate the problem I have been having.
In Dan Slage's fix, he has the following:
Get
If _SelectedCategory Is Nothing Then
Dim objCookie As HttpCookie = Request.Cookies("DNNEvents")
If objCookie Is Nothing Then
_SelectedCategory = ""
Else
Me.SelectedCategory = objCookie.Values("Cat" & ModuleId.ToString)
End If
End If
Return _SelectedCategory
End Get
The problem is that sometimes objCookie.Values("Cat" & ModuleId.ToString) was returning Nothing, and thus returning _SelectedCategory as Nothing. This cause the events list to be 0 length, and, in the calendar view for me, the events wouldn't show up (because it found no events in category Nothing).
To "fix" it I changed it to this:
Get
If _SelectedCategory Is Nothing Then
Dim objCookie As HttpCookie = Request.Cookies("DNNEvents")
If objCookie Is Nothing Then
_SelectedCategory = ""
Else
Me.SelectedCategory = objCookie.Values("Cat" & ModuleId.ToString)
If _SelectedCategory Is Nothing Then
_SelectedCategory = ""
End If
End If
End If
Return _SelectedCategory
End Get
That way if _SelectedCategory is STILL Nothing after looking for the cookie, it will be set to an empty string. However, once I added those three lines, the offending line (Me.SelectedCategory = objCookie.Values("Cat" & ModuleId.ToString)) is returning an empty string instead of Nothing... even after I delete all of my cookies in IE. So my fix isn't really doing anything now, but theoretically if Me.SelectedCategory is set to Nothing again, _SelectedCategory well be set to an empty string.
The real crux here is that somehow ModuleId is returning -1 instead of my real module id. Don't know how that is happening, but it is and it seems to be the REAL culprit here.
Hopefully this helps out all of you who have access to the source code to fix it.