++++ 1 . Agriculture - Common organization of the markets - Export refunds - Advance payment - Erroneous release of the security - Effects - Maintenance of the exporter' s obligations - Error taken into account for the purposes of the grant of an extension of time to the exporter for the submission of documentary evidence of exportation ( Commission Regulation No 2730/79, Art . 25 ) 2 . Agriculture - Common organization of the markets - Export refunds - Submission of documentary evidence - Period prescribed by the regulation exceeded - Grant of an extension of time authorized for the customs documents alone - Exporter required to give valid reasons ( Commission Regulation No 2730/79, Art . 31(2 )) 3 . Agriculture - Common organization of the markets - Export refunds - Advance payment - Documentary evidence of exportation - Period prescribed for the submission of documents exceeded - Loss of the security - Principle of proportionality - Breach - None ( Commission Regulation No 2730/79, Art . 31(1 ) and ( 2 ))