DIIOP crash problem

We have a Domino server 6.5.3 FP1 running in our working environemnt.After we enable the DIIOP task and run for a while,following error appear in the domino server console. “AllocHandle: OUT OF PRIVATE HANDLES! – pid 0000C18 Handles used so far 6399, Maximum handles = 16508, error = 0x107”.

After that,only the DIIOP task crash and domino server run properly.

After that,if we disable the DIIOP task.The same error message did not appear in the console.

Therefore,we would like to know if there were any way could fix this problem.