Java Development Tools

hi jdev 11.1.1.5.0. groups.

i have some problem with af:table row selection property and display row property.

Is it framework had any rule using these two property with an certain dedicated combination.

if i hit insert button, and i make scroll means i get this error.

 <af:table value="#{bindings.Prospects1.collectionModel}" var="row"
                    rows="#{bindings.Prospects1.rangeSize}"
                    emptyText="#{bindings.Prospects1.viewable ? 'No data to display.' : 'Access Denied.'}"
                    fetchSize="#{bindings.Prospects1.rangeSize}"
                    rowBandingInterval="0"
                    filterModel="#{bindings.Prospects1Query.queryDescriptor}"
                    queryListener="#{bindings.Prospects1Query.processQuery}"
                    filterVisible="true" varStatus="vs"
                    selectedRowKeys="#{bindings.Prospects1.collectionModel.selectedRow}"
                    selectionListener="#{bindings.Prospects1.collectionModel.makeCurrent}" id="t1"
                    partialTriggers="::ctb1 ::ctb2 ::ctb3 ::ctb4 :::ctb5 :::ctb7 :::ctb6 :::ctb40"
                    editingMode="clickToEdit" styleClass="AFStretchWidth" first="1"
                    immediate="true" displayRow="selected"
                    rowSelection="single">

 insert button code
<af:commandToolbarButton
                                       text="Insert"
                                       disabled="#{!bindings.CreateInsert.enabled}"
                                       id="ctb5" icon="/Images/add.png"
                                       disabledIcon="/Images/add-disable.png"
                                       action="#{backingBeanScope.MKG1010A.InsertOnProspects}"
                                       partialSubmit="true"/>

sometimes it make fires. sometimes may not.

why am doing like this i want perform insertion at very very first row

Important thing: dnt want any scroll see that first row what i means is:
if i use display row as first. while hitting insertion insertion perform first row. but i want to scroll up towards to see that.

see the pics.
http://imageshack.us/photo/my-images/100/oneselection.png/

I inserted an row. but it is top, when i able to scroll see that means. the error throwing.