Ya lo pude solucionar
tuve que utilizar flags, si no era imposible, entraba en loops infinitos y demás yerbas...
aca les pego el codigo por si a alguien algún dia le sirve :-p
Private Sub TaskPane1_FrameExpanding(ByVal sender As Object, ByVal ce As VbPowerPack.TaskPaneCancelEventArgs) Handles TaskPane1.FrameExpanding
If (ce.TaskFrame.Name = "tskModulos") And (FlagModulos = "") Then
tskAdmin.IsExpanded = False
FlagModulos = "Expanding"
End If
If (ce.TaskFrame.Name = "tskAdmin") And (FlagAdmin = "") Then
tskModulos.IsExpanded = False
FlagAdmin = "Expanding"
End If
End Sub
Private Sub TaskPane1_FrameExpanded(ByVal sender As Object, ByVal e As VbPowerPack.TaskPaneEventArgs) Handles TaskPane1.FrameExpanded
If FlagModulos = "Expanding" Then
FlagModulos = ""
End If
If FlagAdmin = "Expanding" Then
FlagAdmin = ""
End If
End Sub
Private Sub TaskPane1_FrameCollapsing(ByVal sender As Object, ByVal ce As VbPowerPack.TaskPaneCancelEventArgs) Handles TaskPane1.FrameCollapsing
If ((ce.TaskFrame.Name = "tskModulos") And (FlagModulos = "")) Then
FlagModulos = "Collapsing"
tskAdmin.IsExpanded = True
End If
If ((ce.TaskFrame.Name = "tskAdmin") And (FlagModulos = "")) Then
FlagModulos = "Collapsing"
tskModulos.IsExpanded = True
End If
End Sub
Private Sub TaskPane1_FrameCollapsed(ByVal sender As Object, ByVal e As VbPowerPack.TaskPaneEventArgs) Handles TaskPane1.FrameCollapsed
If FlagModulos = "Collapsing" Then
FlagModulos = ""
End If
If FlagAdmin = "Collapsing" Then
FlagAdmin = ""
End If
End Sub