error ERR_WIS_30272 while reading data provider results

We are using BOXI 3.1 SP2 and SP3.

An application opens webi report documents with the BOXI report engine java api.

For some webi reports we get the following exception:

com.businessobjects.rebean.wi.ServerException: Maximum character output size limit reached. Contact your BusinessObjects administrator. (Error: ERR_WIS_30272)     at com.businessobjects.rebean.wi.occa.XMLviaOcca.getDPResultsExAsStream(Unknown Source)     at com.businessobjects.rebean.wi.occa.OccaDataProviderComAdapter.getDataProviderResults(Unknown Source)     at com.businessobjects.rebean.wi.occa.OccaDataProviderComAdapter.getResultAsBlob(Unknown Source)     at com.businessobjects.rebean.wi.RecordsetExImpl.<init>(Unknown Source)     at com.businessobjects.rebean.wi.DataProviderImpl.getResult(Unknown Source)

Here the access:

                       // result                        flowCount = dp.getFlowCount();                        rowCount = dp.getRowCount();                        Recordset rS = dp.getResult(0);                        if(rS != null) {                                :                         } 
dp is of type DataProvider

The call to getResult(0) causes the exception.  The values for flowCount and rowCount are e.g-:

flowCount: 1       rowCount:  61608

flowCount: 1       rowCount:  24488

The only information I need from the Recordset that represents the data provider result is the column name of each result column.

How can I read the list of result columns from a data provider without getting this exception?

Any help is appreciated.

Thanks,

Bernd