Document Level

Creating an Excel Workbook with a Custom Ribbon

This can be achieved by embedding the XML markup into the Open Office XML file.
Using the Custom UI Editor will build the relationships automatically.
There are two ways you can do this:
1) CustomUI Editor
2) NotePad

Add a DoEvents statement immediately after invalidating the ribbon

Public Sub InitialiseAddInsRibbon(ribbon As IRibbonUI) 
   set mRibbonUI = ribbon 
End Sub 

Public Sub RefreshAddInsRibbon 
   mRibbonUI.Invalidate 
   DoEvents 
End Sub 

Use a single procedure for similar callbacks
Button_getVisible - handles all visibility callbacks then use a select-case

Always refer to a controls ID, never the Tag
2007 - you can change the visibility of a separator at runtime
custom icon sizes (32/16) generates blank error messages
Changing icons dynamically - getImage callback

This is the only way of customising Outlook 2007
The customisations are defined at design-time and stored as an XML file in the Office Open XML file format.
Using a document-level solution in PowerPoint (.ppam)
Using an application-level template in Word (.dotm)