slow to open Excel 2007 and Word 2007 (MIS stumped)

Hello,

I have been having this problem, when I asked our MIS department for help,
it has them stumped also (at least I take their silence to mean that they
don't want to admit they don't know what is wrong). When I try to open an
Excel or Word document it takes an extremely long time to open the file. But
it I open Excel or Word first then locate the file to open it will come up
right away.

This only happens with Excel and Word. The work computer is on a network,
it is Office 2007 running on Windows XP (I think). Is there anyway to fix
this, it has been happening for almost 2 weeks now.