I just had a terrible problem with the softlayer dns cluster functionality on cpanel and spent 2 hours fixing it... Currently, i use 2 cpanel DNS only servers as my primary and secondary DNSs, however yesterday i decided to use the Softlayer DNS service to act as a ns3 and ns4 for my servers. So, i setup softlayer as a dns cluster and proceed to syncronize my DNS records by selecting "Synchronize DNS Records" and "Synchronize all zones to all servers".
It all seems to work as intented, but today i found out that this had messed up my DNS records!! All my NS records was changed to ns1.softlayer.com and ns2.softlayer.com, and my MX records were completly wasted!
This is invalid so my clients were unabled to receive any e-mails and since my TTL was 86400, it will persist on some cases for the whole day.
Right now i am changing all my TTls to 3600 with a script, but the damage was done already. Anyway, just a heads up in case you try to fix things that are not broken like i did. Also, cpanel please fix this. Thanks