hi
it could be that the srp key you are trying is linked to another rim domain ie srp.uk.blackberry.net etc.
i had a smiliar problem i installed a new BES and set it to srp.uk.blackberry.net, when ever i was putting the srp info it would not accept it and would default to the temp key. i later found out the old server was set on the srp.us.blackberry.net and therfore i had to set the new server to this which i did and it accepted the key.