Cube error

[Sarayucog]

Hi all,

I have retrieved the data for one week and now I am using incremental update option to fetch the next day's data. I have checked an option in cube properties and Iahve changed my iqd to retrieve the next days data, but its giving an error. The error is

The wrong ID stamp was detected on cube_name.mdc. This often happens when the model is not saved after creating a PowerCube.

Its fetching some lacs of records but in mid of the process its giving the above error.

Could you please tell me this one. Its urgent...

Thanks in advance
Sarayu