DNS record creation fails

[StayAllive]

Hello All,

I get some weird errors when adding DNS records...

When trying to add a TXT or MX record to my domain I get the error that a similair CNAME(!) record already exists...

Example:
something.domain.com MX mxa.mailserver.com (This one is OK)
something2.domain.com MX mxa.mailserver.com (This one fails with the error above)

This should work right? Same goed for identical TXT records for different subdomains!?

I'm running 11.5.30 Update #21 on CentOS 6.