>>>I would start with looking into an error message/status which should be in client properties, I guess
>>
>>Right. I checked the properties of Client, could not find anything.
>>
>>Thanks.
>
>You should have error in the exception in the catch block then

Right... In fact it turns out that it's Google that locks the access to the account when it thinks the account it's bein hacked. There seems to be a procedure for this kind of situations. Thank you very much for your help.