Hello and thank you for your help/advice in advance,

I am having trouble within a custom skin that I created a while ago.  This skin has a bottom pane which has 4 html modules within it.  Our content editor went to add another module to the bottom of the same pane.  When she did - she found that the edit ddl would not show the list - therefore she could not edit like she usually does.  So I looked into the google chrome tools and found that the last module was outside the div of the pane?  So I deleted it and added again - same thing?  Every  time I added another module to this pane at the bottom - it would be placed outside the div of the pane.  We found that we could either shuffle the order of module and edit no problem though.  Another solution was that I placed another pane just below that one and added module - and it worked.  Does anyone know the cause of this issue?