Index: src/com/iver/cit/gvsig/geoprocess/impl/dissolve/fmap/SingleFieldDissolveCriteria.java
===================================================================
--- src/com/iver/cit/gvsig/geoprocess/impl/dissolve/fmap/SingleFieldDissolveCriteria.java	(revision 39491)
+++ src/com/iver/cit/gvsig/geoprocess/impl/dissolve/fmap/SingleFieldDissolveCriteria.java	(working copy)
@@ -77,6 +77,7 @@
 import com.iver.cit.gvsig.fmap.drivers.ILayerDefinition;
 import com.iver.cit.gvsig.fmap.drivers.SHPLayerDefinition;
 import com.iver.cit.gvsig.fmap.layers.FLyrVect;
+import com.iver.cit.gvsig.fmap.layers.SelectableDataSource;
 import com.iver.cit.gvsig.geoprocess.core.fmap.DefinitionUtils;
 import com.iver.cit.gvsig.geoprocess.core.fmap.SummarizationFunction;
 import com.iver.cit.gvsig.geoprocess.core.fmap.XTypes;
@@ -234,13 +235,22 @@
 				getFieldIndexByName(dissolveField);
 			int fieldType = layer.getRecordset().
 				getFieldType(dissolveFieldIndex);
-			int fieldLenght = DefinitionUtils.
-				getDataTypeLength(fieldType);
+			//int fieldLenght = DefinitionUtils.
+			//	getDataTypeLength(fieldType);
+			SelectableDataSource recordset = layer.getRecordset();
+			FieldDescription[] recordsetFieldsDescription = recordset.
+				getFieldsDescription();
+			int fieldLength = recordsetFieldsDescription[dissolveFieldIndex].
+				getFieldLength();
+			int fieldDecimalCount = recordsetFieldsDescription[dissolveFieldIndex].
+				getFieldDecimalCount();
+			
 			description.setFieldName(dissolveField);
 			description.setFieldType(fieldType);
-			description.setFieldLength(fieldLenght);
+			description.setFieldLength(fieldLength);
 			if(DefinitionUtils.isNumeric(description)){
-				description.setFieldDecimalCount(DefinitionUtils.NUM_DECIMALS);
+				//description.setFieldDecimalCount(DefinitionUtils.NUM_DECIMALS);
+				description.setFieldDecimalCount(fieldDecimalCount);
 			}
 			fields.add(description);
 		} catch (ReadDriverException e) {