Can not open buffer file when backuping Sybase DB.

[albert_hua]

Hi, every one:
When I executed one Sybase DB backup session which has 22 databases to backup totally with OmniBack II, I found one individual database backup failed and the error message was
[CSSPROD:dbsaspp1] Unable to open buffer file
[CSSPROD:dbsaspp1] Sybase backup failed

Could you tell me the detailed info about this error message? And how can I find more details about such kind of error messages? Could anyone tell me the relationship between the buffer file and the Sybase DB because I am not very familiar with DB. Thanks a lot.
Any advise will be greatly appreciated.

Rgds.
Albert