WMTNWeb is not working properly


We are Using Integration Server v 4.6. WmTNWeb is not working properly when we are searching documents using this via browser. It is displaying all the doucments with selected query.
If I click on date link(viewdocdetail.dsp) of perticular document it is displaying some times details of that document and some times it is displaying empty page(no details). My question is why it is working some times and it is not working some time. We did not change any thing in side the code.
I would like to know what we need to do to solve this.