Speed dials and call logs are restricted by default in the latest releases. You need to edit your 46xxsettings file to allow users to add speed dials.
############## APPLICATION ACCESS SETTINGS ###############
##
## These settings restrict access to certain applications.
## APPSTAT is not supported on 96xx SIP phones.
##
## When APPSTAT is set to 0, Call Log and Redial are
## suppressed and changes to Speed Dial/Contacts are not allowed.
##
## When APPSTAT is set to 1, Call Log, Redial and,
## Speed Dial/Contacts work without restrictions.
##
## When APPSTAT is set to 2, Call Log is suppressed.
## For Redial the Last-6-numbers option is suppressed
## and changes to Speed Dial/Contacts are not allowed.
##
## When APPSTAT is set to 3, changes to Speed Dial/Contacts
## are not allowed.
##
## SET APPSTAT 1
Remove the 2 #'s in front of the SET APPSTAT 1 line and restart your ip set to load the new setting. Hope this helps.