ODBC Error Handler- Connection: Distributed Relational Database Architecture (DRDA) protocol error

I’m using ODBC to connect to an iseries machine, and occaisionally I get the following error message, but have no idea what it means:

ODBC Error Handler- Connection: Distributed Relational Database Architecture (DRDA) protocol error

Can anyone help with this or point me int he right direction? I’ve done searches on the forums before for this, but have not found a clear answer as to what might be the problem, or what to look at.