UC540 - CoLine destination changes randomly

[croenbaugh]

I am using a UC540 with four FXO lines.  On the inbound dial plan I have directed these lines to go to a blast group.  Every few days the two mosted used lines revert to Co_line from Blast_group.

I don't know why and it is driving me crazy.  I am using SPA 303 phones with both of these lines assigned to a button.  We also have an SIP trunk set up. The outboud dial plan uses the SIP trunk first and then the FXO lines. 

Any ideas?

Regards

CR

[paolo bevilacqua]

Update IOS if it not current.

And the check if still happens when not using CCA.