why shared workbook in excel goes off sharing and creates a temp

[shared workbook]

dear sir,
i have a small network in my office, iam working with excel, its
fine but
sometimes,sharing a shared workbook goes off and automatically a temporary
file
is creating leaving the original file. waht should i do to run excel
smoothly on my
network. please give the suggestion, waiting for ur response .
thanking you sir,

faithfully,

m.d.jahangeer pasha.