Hi Frank,
Thanks for your support.
Yes I've already tried all the procedures posted above, but nothing's changed.
The only old files i'm able to recover are those stored on a backup HD (previous versions).
Same problem with Pages and Keynote: some files (not able to explain why some yes and some no) are not valid when i try to open them. Sometime appears a message "file is damaged", other times "Pages is not able to open...".
In fact, all this files are stored on a G4 PowerMac with MacOSX Server 10.4, double HD in mirroring mode.
When i opened some packages i saw a strange permission allocation: while the original creator was me (mjf), files and folders were assigned to the server administrator account (abcIT), group same, other no allowed to any changes.
Obviously i changed this setting, allowing everyone to read and write to those files... but nothing happened!
I've tried to copy those files on local machine as you suggested me... same result!
Thanks anyway
p.s. even i hate Microsoft and found Pages and Keynote as a good tool for my everyday work, even those are not a flop, sure i cannot trust in them for my documents (fortunately i always do a pdf copy of them)