Out Of Memory issue in axis2 1.4

[Shehan Simen]

Hi,
I am getting this out of memory exception from server side when I try to send 
attachment using mtom.
I did everything as mentioned in the http://wso2.org/library/264
But it is helpless.
I am using tomcat 5.5.23 and jdk 1.5 (I am restricted to this, cannot change 
them)

My axis2 xml has settings as:
<parameter name="enableMTOM" locked="false">true</parameter>
    <parameter name="enableSwA">false</parameter>

    <!--Uncomment if you want to enable file caching for attachments -->
    <parameter name="cacheAttachments">true</parameter>
    <parameter name="attachmentDIR">C:/Program Files/Itree/IACD/log</parameter>
    <parameter name="sizeThreshold">4000</parameter>

I cannot send 5mb file. I set the client time out to 10 mins, but it does not 
help.
Can anyone please help me? Whats wrong with axis2?

Thank you.

Regards