excel worksheet opening problem

[sunita]

I opened a particular excel file - which is accessed
freqently - the worksheet does not appear on the screen
whereas the taskbar shows "ready", the name box shows the
cell address and the formula also shows the value in the
cell. I copy the file to a new file and try opening the
new file but the same problem persists.
The other excel files are opening normally.
To my surprise the next day I find that the file opens
normally.