Excel formatted planning forms NOT consistantly displaying in Planning

We are developing some planning forms which we have been formatted in Smart View and saved out to planning.

We are experiencing where some folks can see the formats in planning and others can't. This is true when using Internet Explorer or Firefox both 32-Bit.

For Example I may see the formats in Firefox and not in Internet Explorer while someone else can see in IE but not FF, someone else can see in FF and IE and someone else can see in neither IE or FF. We all seem to be on the same versions of IE and FF.  It must be a client and we've looked at various settings, clearing cache etc but nothing is leaping out to us.