UploadHandler never called while using dhtmlxvault

Iam using dhtmlxVault component. I have just tried to run the the basic example what is given by the dhtmlx, one change is I have used struts.
For those three handlers uploadHandler,getInfoHandler,getIdHandler. I have three different actions in my struts action class . I have declared those actions in struts config file.
When i upload the file it calls first getIdHandler ( content typeapplication/xml; charset=UTF-8) & then it calls getInfoHandler method (content type is application/x-www-form-urlencoded;charset=UTF-8).
After that it gives error on the component saying EROR just below file name. No stack trace nothing & it never calls third method.
Iam not sure why third method is not called

I read similar kind of the issue in the forum. In the end response was
In fact it was an issue with struts. When files were small enough to be transfered before the first call to the uploadHandler script, struts already took its hands on the file. Therefore parseRequest returned an empty list because struts did already take care of the file. Disabling that struts behavior solved the issue with small files.

I dont know what he meant?
Can some tell what could be reason ? how to fix this issue?

What version of Struts do you use?
Basically, you should disable file parsing by Struts. It’s one of its filters. If you give me your Struts version i could try to find the right one for you.

I have just verified . We are using struts-2.0.

are you saying that we have to disable this interceptor
. This interceptor comes with struts 2 default stack.
Please confirm.