Editing sharepoint documents through APM

Hi, I am having an issue when editing sharepoint microsoft documents through my F5 APM setup. If I open them on the inside of my network, I am asked if I want to open in edit or read only mode. If I access using the F5 APM I am asked to open with default application or save the document. Seems that I recall reading somewhere these is a way to control this behavior, but am unable to find that information again.

Anyone have thoughts on this?

Thanks, Danny