OAM audit log issue. Unable to get unique sequence number

I set up OAM with audit logging enabled on the DB.  After several months, I started getting this error:

<IAU:Unable to write Audit Event for Type: OAM>

<IAU:Unable to get a Unique Sequence Number using query: SELECT ID_SEQ.NEXTVAL from dual>

ID_SEQ.NEXTVAL = 2,490,000,000   (and counting)

The maximum value of IAU_ID in the OAM and IAU_BASE table is (2,147,483,631).  So, I know I'm not running into a unique constraint issue.

The datatype of the IAU_ID field is NUMBER   (So, the value should be able to exceed 2,147,483,631).  But, my guess is that it's been arbitrarily capped at 2^31-1  (