I am having a problem in power point. The problem is when some one has a file open and I open it, and try to view the images as a slide show. When I select the view slides from the beginning tab. I get a file is being modified by xxxxx (persons name) do you want to open a read only copy. When I select yes it freezes and I get the following error message.

error signature App name: powerpoint.exe App ver:12.0.6000.1000 App stamp: 4de50c7e Mod name:crs_powrepoint.dll Mod Version 2.1.0.0 mod stamp4e8f7398 fdebug:0 offset00006331

in event viewer I get:
faulting application powerpoint .exe,Version12.0.6600.1000,Stamp 4de50c7e,Faulting module crs_powerpoint.dll,version 2.1.0.0 stamp 4e8f7398,debbug?0 , fault address 0x00006331
can anyone help me to be able to view slide show of a file if it is open by another person.