Messages getting stuck in Delivering status in AE

Hi all,
Recently we are coming across messages that go into Delivering status. These messages mostly belong to File Sender/Receiver Adapter but not confined to them. Here is the audit log of one such message:
2011-03-21 10:01:55 Success Write to file "/usr/sap/ZX2/EXT/XI_INTERFACES/SCP2PIF016/NOT_PROCESSED/goodsReceiptPosting_InvalidRecords20110321-100155-650.xml" as binary, size 1949 bytes
2011-03-21 10:01:55 Success File processing complete
2011-03-21 10:01:55 Success MP: Leaving module processor
2011-03-21 10:01:55 Success The message was successfully delivered to the application using connection File_
2011-03-21 10:01:55 Error Setting the message status to DLNG failed, due to: Error updating status..
On searching in SDN I found one work around-- to restart Messaging Service in Visual Admin. This did work as the messages got processed after that. But, the problem seems to be recurring now(once in every two days).
Can any body shed some light on this to find the permanent fix?
Thanks a lot,

Make sure you have set the MaxThreadCount parameter to 350 or higher depending of the case and of the resources available.
To increase the parameter, please follow the instructions below:
1. In the left frame choose Server -> Kernel -> ApplicationThreadManager
2. In the tab Display Configuration (right frame) choose Switch between view and edit mode to activate the edit mode.
3. The parameter MaxThreadCount must be set to 350.
4. You will then need to restart the J2ee
For reference see note #937159 - XI Adapter Engine is stuck
For specific setting to an adapter can be done by going to the Visual Administrator -> Services -> SAP XI AF Messaging
Look at the property 'Messaging connections' here you will see the following queues:
Send.maxConsumers (asynchronous sending - outbound)
Recv.maxConsumers (asynchronous receipt - inbound)
Call.maxConsumers (synchronous sending - outbound)
Rqst.maxConsumers (synchronous receipt - inbound)
Depending on where the bottleneck is occurring (i.e. too many entries in the Send.maxConsumers) you can increase these parameters.
Example of parameter value syntax (sample for FILE adapter):
(name=FILE_, Send.maxConsumers=10, Recv.maxConsumers=10, Call.maxConsumers=10, Rqst.maxConsumers=10)
For reference see note:
#791655 - Documentation of the XI Messaging System Service Properties
And see the link:
Caio Cagnani