Incremental Backup backup all file

Hi.!

I have backup exec 2012 version 14.0 Rev. 1798(64bit)

and create backup job for file server.

Full -> Incremental

Full: Once a month

Incremental: every 1day

It worked fine.

But a few day ago, differencial backup task backup all file.

Review the log

Usually full backup size is about 223GB and incremental size is about 1GB.

Now incremental backup size is 224GB every day.

No special option or configure in job.

I just added disk storage which is MSA60 encluser through the SAS cable.

It was configured RAID 5 and 12ea of 300GB SAS HDD.

How I fix it??

Please help.