[Freeswitch-users] Memory leak in mod_nibblebill or in ODBC core?

I want to utilize nibblebill features for prepaid support, but as soon as I enable nibble billing with set nibble_rate=XXX set nibble_account=NNNNNN set enable_heartbeat_events=60 in dialplan, FS process begins to eat more and more memory, RSS grows from 23M to 100M and more after processing few thousands calls and continues to grow. If I comment out those 3 lines from dialplan, then FS RSS grows from initial 23M to 50-60M (depending on the number of concurrent calls) and stays at this value, no memory leaks. Do anybody use mod_nibblebill? I'm experiencing this problem with all svn versions I tried including latest git version.