ip 501 url call is disabled

I have about 5 customer phones at one site that are now giving me url called disabled.
Polycom Ip 501
the tftp downloads were not working. I took one phone to my shop and it download the tftp info fine.
So i setup a ftp server put the config files from the tftp to the ftp folder and set the phone for ftp.
It worked fine.
I took the redid phone back to the customer and it download the ftp info and worked fine.
I tried to change the existing tftp phones to ftp and the download the new which they would not do before but they still give the same error
URL CALL iS DISABLED ..
I cannot figure why if I bring the phones to the shop and download the info what is different. aahhhh
Thanks,