VersionConflictException when calling the ‪getFeed(mySpreadsheetURL, ListFeed.class) function

[Grivos]

Hi all,
I'm using an app i wrote in Java to access a certain spreadsheet.
Everything went fine for months until today when i got the above exception..
I thought that a VersionConflictException might be thrown when trying to 
update an entry, but I'm only trying to retrieve a feed!
Please help!