While I can export to a PDF I cannot export to Excel or Word.
There is a confirmed bug in Access Services, IE, and Office that causes this behavior in certain configurations. We have been working with Microsoft to resolve it but as of yet they have not published a fix, just the workaround of using the Access 2010 runtime client to generate the reports in Word & Excel (you do not need to purchase Access 2010 for each client but you do need the runtime). PDF always works fine.
The most interesting part of this problem is that it all works fine on the Mac with Safari and Mac Office.