Essbase EIS Data load buffer [3] does not exist - only sometimes ?

I've been checking the logs and we get the commit happen most times, but every now and then we get the "Data load buffer [3] does not exist"

This is very unpredictable, it's a cube built via EIS and Essbase 11.1.2.2 64bit on Solaris 10, conencting via Teradata ODBC Driver.

The actual data load seems to complete, but it fails at the commit with the data load buffer error.

We've had the networks and SAN checked out, no issues reported, no issue with running out of disk space or memory either.

Everyone we've had look at this seems to point to Essbase/EIS, any other ideas ?