I've had a bit of trouble getting one A record setup and I think I've come across a bug.

Setting the host to blank (i.e. refering to example.net), runs successfully and validates. A dig performed to the server however returns nothing.

Setting the host to the parent domain (i.e. 'example.net') fails without warning, and doesn't save etc...

Setting the host name to how dig makes it query (i.e. 'example.net.') runs okay, and validates (except on the DNS manager it appears without the trailing dot) and seems to kill all the other records.

Also seems that updates can go nasty if you make them while the domain is 'on', you actually have to go when your finished and change it to edit, and then back to on.

Hope the problem can be found/fixed.