Problem reading generic profile from AC6000 meter

I'm trying to read information from generic profiles on ACE meter.

(I'm using Java ME 1.3)

I can read information from Load profiles (0.0.99.1.0.255 & 0.0.99.1.2.255)

However, when I try to read the columns from Data of billing period (0.1.98.1.0.255) I get a strange error.

Here is the tracing of the communication whith the meter:

09/07/19 13:43:13.569 - <- 7E,A0,1C,00,02,00,23,03,70,0A,59,E6,E6,00,C0,01,81,00,07,00,01,62,01,00,FF,03,00,C8,47,7E
09/07/19 13:43:14.159 - -> 7E,A0,0A,03,00,02,00,23,35,48,4D,7E
09/07/19 13:43:15.162 - <- 7E,A0,1C,00,02,00,23,03,70,0A,59,E6,E6,00,C0,01,81,00,07,00,01,62,01,00,FF,03,00,C8,47,7E
09/07/19 13:43:15.181 - -> 7E,A8,8C,03,00,02,00,23,36,BF,8C,E6,E7,00,C4,01,81,00,01,42,02,04,12,00,04,09,06,01,00,62,86,01,FF,0F,00,12,00,00,02,04,12,00,07,09,06,00,00,62,85,02,FF,0F,02,12,00,00,02,04,12,00,07,09,06,00,00,62,85,01,FF,0F,02,12,00,00,02,04,12,00,07,09,06,00,00,62,85,3D,FF,0F,01,12,00,00,02,04,12,00,07,09,06,00,00,62,85,3D,FF,0F,02,12,00,00,02,04,12,00,07,09,06,00,00,62,85,3E,FF,0F,01,12,00,00,02,04,12,00,07,09,06,00,00,62,85,71,8C,7E
09/07/19 13:43:15.184 - <- 7E,A0,0A,00,02,00,23,03,91,89,42,7E
09/07/19 13:43:15.225 - -> 7E,A0,0A,03,00,02,00,23,97,50,CB,7E
java.lang.IllegalArgumentException: position
at gurux.dlms.GXByteBuffer.position(GXByteBuffer.java:155)
at gurux.dlms.GXDLMS.getData(GXDLMS.java:2566)
at gurux.dlms.GXDLMSClient.getData(GXDLMSClient.java:1906)
at DLMSProtocol.GXCommunicate.readDLMSPacket(GXCommunicate.java:185)
at DLMSProtocol.GXCommunicate.readDataBlock(GXCommunicate.java:239)
at DLMSProtocol.GXCommunicate.GetColumns(GXCommunicate.java:446)

This seems to me like some problem in the decoding of the last packet from the meter..

Can somebody please help me to solve this problem?

Thanks,
Nadav