Wrong BGP identifier

I have a cisco router which runs iBGP and eBGP as AS 64512. This router peers with a router running as AS 64610. Config:

Router1

Router bgp 64512 neighbor 5.5.5.5 remote-as 64610 neighbor 5.5.5.5 update-source loopback0

ip route 5.5.5.5 255.255.255.255 10.0.60.2

Router 2

Router bgp 64610 neighbor 1.1.1.1 remote-as 64512 neighbor 1.1.1.1 update-source loopback0

ip route 1.1.1.1 255.255.255.255 10.0.60.1

iBGP works just fine. But for the eBGP I get wrong BGP identifier.

Any ideas?