Issue synchronisation attribut Delta Synchronization

Hi, 

I have a weird issue in a synchronisation of an attribute from FIM to AD. 

I explain my problem, I manage the attribute userAccountControl from AD to FIM. 

I have another boolean attribute which enforce the activation of a user 

So we suppose that we have a person on FIM portal with userAccountControl (66050), I force the activation 

so I export the value 66048 in AD it's OK for this step. 

When I run a Delta Import + Delta Synchron from AD , then an export on FIM MA my userAccountControl is not updated as in AD.

When I run a full preview in AD MA for that identity i see that a change will be made on FIM MA, I commit it and export on FIM MA and the result is correct in FIM (66048)

But when I run a delta synchro in AD MA nothing is done in FIM .

Any idea please !!! 

Thanks