Global Directory/Phonebook Issue Aastra Handsets

Hello all,

I am trying to get a global directory/phone book setup on a FreePBX installation but have been having some issues with certain handsets and was wondering if someone could shed some light as to what the issue could be or an alternative method please?

We use Aastra handsets and in the past this has worked for the 53i, 55i and 57i models. Normally we place a file on the phone server /var/www/html/aastra/asterisk/contacts.php and this points to a txt file on the server in the following directory /var/cache/aastra/contact.txt. The txt file just has peoples name and phone numbers in it. I will paste a link to the .php file at the end of the post. On the Aastra handset we create a XML button like the following and this allows us to do a lookup on the txt file. We can browse through all pages etc to call a contact off of it.

h ttp://ip.of.phone.server/aastra/asterisk/contacts.php

On the Aastra 6867i and 6869i phones the directory button seems to partially work. It will show you a list of contacts but you cannot changes pages as other buttons on the screen are missing like next page.
Would anyone be able to advise on this issue or suggest an alternative method? If another method would be the best option it would be good if it was a global directory so one change applies to all users meaning it can be managed easily.

Thank you all in advance and hopefully I have not missed too much out.

h ttps://dl.dropboxusercontent.com/u/29346969/contacts.php