DSM 4.0 Error on Download Station task

[mrsynology]

My DS211J experience BT task error after upgrade to DSM 4.0 (2198). You can observe the tasks running properly from the resource monitor then stop or report error on status after a few hours of running. Is there anyone experience similar problem on DSM4.0?

[mrsynology]

Another observation is high frustration of network in Resource Monitor. The pattern is liked zip zap:

Time(S) DL/UL
01 212KB/s
02 5.5KB/s
03 185Kb/s
04 1.5KB/s
05 195KB/s
... ...

[mrsynology]

The system can up and running for 55 minutes then all BT task down to show Status in Error.

[mrsynology]

All eMule tasts are Paused.

[mrsynology]

Further supplement, there is about 10 BT task and memory & CPU is about 45%