FSM 5.7.6 Column '' does not belong tot table xxx on save

I have Added a extension table to the place table. then added the new fields to the place screen. but when i go an update the one of the fields i am getting this error 

“Column '' does not belong to table imax_place_extension.”

Can anyone suggest where this error is coming from.

If i try to post the update message in the XML Poster i get the same message.

<perform_batch>
 <sequential_dependent>
 <update_place regex_validated="true">
 <place>
 <update>
 <original_place>
 <place_id>20759</place_id>
 </original_place>
 </update>
 <place_id>20759</place_id>
 <e_ref1>1000</e_ref1>
 </place>
 </update_place>
 </sequential_dependent>
</perform_batch>

<perform_batch_result>
 <update_place_result>
 <result type="Exception">
 <error>
 <system_error>
 <severity>ERROR</severity>
 <message>Column '' does not belong to table imax_place_extension.</message>
 </system_error>
 </error>
 </result>
 </update_place_result>
</perform_batch_result>

if i update another field on the extension table i am not getting the error

<perform_batch>
 <sequential_dependent>
 <update_place regex_validated="true">
 <place>
 <update>
 <original_place>
 <place_id>20759</place_id>
 </original_place>
 </update>
 <place_id>20759</place_id>
 <e_customer>20759</e_customer>
 </place>
 </update_place>
 </sequential_dependent>
</perform_batch>

<perform_batch_result>
 <update_place_result>
 <place>
 <place_id>20759</place_id>
 <e_customer>20759</e_customer>
 </place>
 </update_place_result>
</perform_batch_result>