Cisco 7861 phone does nothing when you press the corporate directory button: just blank screen and no error message

[Sarg .]

Hello everyone, 

we recently deployed some Cisco 7861 (78xx.10-1-1SR1-4) phones running on cucm 9.1.2.10000-28 . What we have noticed is that after a while, the corporate directory stops working. But if we reboot the phone, it starts working again. 

Another thing we noticed is that when the phone stops access corporate directory, the phone's webpage stops working but if you reboot the phone, then you can access the phones web page again. 

Cisco actually tried to enable debugs while the phone was broken but the phone did not produce any logs, but if you reboot the phone, then it starts producing logs. 

I have a TAC case for but I just wanted to find out if there are other people here facing this same problem. with 78x phones?

Thanks 

Maxwell 

[Ian Freely - Shared Account]

Yeah we're running the latest version too - it has not resolved it for us. They are talking about an engineering release for us, but we are struggling with TAC they don't seem to understand times zones and keep putting engineers on it when we're not available