I struggle with my E680 sms issue several days and it was fixed by reading articals in this site, cheers!

my E680 has about 100 contacts, 1500 sms. Several days before it failed to remove sms. each remove action took about 10 minutes or more long. some times it give message about "Memory Full".

After read articles from this site, I fixes this issue by following steps:
1) sync contacts to computer
sync all my contacts to computer using EzxSync

2) reload the backup 'contacts|sms' database files (maybe also could give "Major Clean", "Major Reset" a try but I do not test it)
telnet to E680 by using usblan and remove /ezxlocal/sysDatabase/*
# rm -f /ezxlocal/sysDatabase/*

copy /.backup/{log.00*|native*.db} to /ezxlocal/sysDatabase
# cp -p /.backup/log.00* /ezxlocal/sysDatabase
# cp -p /.backup/native*.db /ezxlocal/sysDatabase
# sync ; sync

reboot E680
# reboot

3) sync contact list from computer to E680
configure EzxSync and make 'contacts' sync from
computer to E680 single direction. after finish sync all my contacts was restore to E680.

Notes:
1. 'contacts|sms' database has size limited so user should clean their contacts, sms to reduce the database, index and logfile do not eat all the space of /ezxlocal. otherwise the database|index would be damaged.

2. user get "Memory full" message can follow this steps to restore their contacts.

3. I wanna the front end of contacts, sms program should also monitor the database,index size and give a warning when close to size limit. it would be nice to end user.