Updating multiple records to Oracle DB

I am using atomic scope to update multiple rocords into Oracle table.
My XML message would be like

<items>
	<item>
		<itemNo>1</itemNo>
		<status>1</status>
	</item>
	<item>
		<itemNo>2</itemNo>
		<status>1</status>
	</item>
	<item>
		<itemNo>3</itemNo>
		<status>1</status>
	</item>
	.
	.
	.
	<item>
		<itemNo>n</itemNo>
		<status>1</status>
	</item>
</items>

My BizTalk application hung up when the Large number of items comes.
like if 500 items comes its hung up.
I could not found any error in event log., and i checked the
Administration console the orchestartion was active.

Any one help me out why this hnug up when large Items come in my
Incomming message?
Thanks in advance.