Oracle DB freezes with wM adapters

Version Details
wM ES 5.0.1
wM EI 4.6
JDBC Adapter 4.6
ADK 4.2.1
We are running a synchronization integration involving a custom buffer table and uses basic notification to trigger of the Integration components. The basic notification is subscribed to by a JDBC adapter. We are also using a custom adapter(developed using ADK 4.2.1) with a pubish and wait step to read off some data from a custom application. The custom adapter also reads data from the same DB which the JDBC adapter is polling for basic notifications. After running for 2 days, the Oracle DB(8.1.7.2) just freezes. Need a shutdown to resume operation. The number of sessions look healthy just before the DB freeze.
Anybody has faced any similar problems before?
Any pointers would be very useful.
Thanks.