Strange fdisk behavior on 5.4-STABLE

[Baldur Gislason]

I have a hard drive in my laptop with a 30GB FreeBSD partition and a few gigabytes of unused space (40GB hard drive).
I wanted to make another FreeBSD partition but when I run fdisk I get this following error:
fdisk: cannot open disk /dev/ad0: No such file or directory

/dev/ad0 does exist and fdisk has no problem printing the partition table, but when run with -u it pretends
the disk doesn't exist.
I had no problems partitioning a USB flash drive.

Any suggestions?

Baldur