Windows – AD DC for the domain could not be contacted

I know there are some question about "An Active Directory Domain Controller for the domain could not be contacted"

An Active Directory Domain Controller for This Domain Could Not be Contacted

An Active Directory domain controller for this domain could not be contacted

,but somehow its not helping me.

Im running a Win 2008 R2 and on this system there are some virtual machines. Installed R2 on VMware server and I was able to put the machine into my domain. After that VirtualBox got installed (newest version) and R2 got installed on it also but Im not able to put the machine into the same domain.

The domain name "mydom" might be a NetBIOS domain name.  If this is the case, verify that the domain name is properly registered with WINS.

If you are certain that the name is not a NetBIOS domain name, then the following information can help you troubleshoot your DNS configuration.

DNS was successfully queried for the service location (SRV) resource record used to locate a domain controller for domain "mydom":

The query was for the SRV record for _ldap._tcp.dc._msdcs.mydom

The following domain controllers were identified by the query:
ccwmlab40.mydom


However no domain controllers could be contacted.

Common causes of this error include:

- Host (A) or (AAAA) records that map the names of the domain controllers to their IP addresses are missing or contain incorrect addresses.

- Domain controllers registered in DNS are not connected to the network or are not running.

I dont get it. Everything is the same as on the other VMWare machine and somehow there are no domain issues. Could be this a VirtualBox issue or did I something wrong on my R2? Its funny, because im able to ping everything and everybody who is in the domain but I get the message that there is no domain like mydom? There is something wrong. Any ideas? Thank you

Edit: If you need any other information, please tell me what else I could post here.

ipconfig /all on the VirtualBox System:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : TestR2
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : mydom

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : mydom
   Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Desktop Adapter
   Physical Address. . . . . . . . . : 08-00-27-6C-62-F9
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::c091:55b6:72e7:3ac4%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.0.2.15(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Donnerstag, 21. Juni 2012 12:17:34
   Lease Expires . . . . . . . . . . : Freitag, 22. Juni 2012 12:17:33
   Default Gateway . . . . . . . . . : 10.0.2.2
   DHCP Server . . . . . . . . . . . : 10.0.2.2
   DHCPv6 IAID . . . . . . . . . . . : 235405351
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-73-40-21-08-00-27-6C-62-F9
   DNS Servers . . . . . . . . . . . : 192.168.22.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.mydom:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : mydom
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

DHCP Server is 192.168.22.1
ccwmlab40.mydom is 192.168.22.6