it looks like you selected the OptionID column from the rsMaterialoptions recordset in step 3 of the manage relational table behavior instead of the checkbox in the repeat region.
double check that the settings in the manage relational table on the update page are the same as for the insert page.
the only difference on the update page will be using the URL Variable for the Main table Join Key value.
nowhere do you use a recordset value in the manage relational table behavior.