Pages v4.0 (727) can't open or save .doc files

Hello everyone,

for a while now I haven't been able to open or save .doc files with Pages. When trying to open a .doc file I get the following message:

"The document "example.doc” couldn’t be opened."

I have tried the following to solve the problem:

1. run Software Update, which told me there were no updates available

2. checked my applications folder to see if Pages was in the iWork '09 folder in order for SU to be able to detect updates (it was)

3. reinstalled Pages from the iWork disc and run SU (which again couldn't detect any updates)

4. deleted the com.apple.iWork.Pages.plist file from the Preferences folder in the user library on the Macintosh HD

I'd be very grateful if someone could point me towards a solution, I've spent an age on google looking for one and haven't found anything useful so far.

Thanks in advance

XtremeFlux