After reading your documentaion "Common Serialized Field Mistakes" my interpretation of this is that once you set a field to be serialized every time you access the field deserializes before you get the strong-type.

Doing this you have to make a local copy and use that. Please explain?

Tks

Yes, every time you access a "serialized" property, the serialized data within the business object's CurrentDataTable is de-serialized and returned. If you type something like this:

MyBO.SerializedBitmap.Width = 50

the business object de-serializes the bitmap, and you set the width on the object that was just de-serialized. However, this line of code 1) does not obtain an object reference to the object that was just de-serialized and 2) does not re-assign the value of the modified bitmap object back to the serialized property (so, the modified bitmap is never re-serialized back into the data table). When working with a serialized field, you need to save an object reference to the object that was pulled out and put it back in to the property when you're done with it.