[c-nsp] BGP sessions won't establish.

[Roy]

Just to bring everybody up to date, the ISP keeps saying its something 
we are doing.  To eliminates any quirks, we have a spare router directly 
connected to the metro ethernet box now.  All the hardware is different 
and we have tried several version of IOS.  The config has been stripped 
down to bare bones.  I have attached the relevant portion.  The first 
session (the neighbor ending in .233) comes up.  The other one (ending 
in .18) fails

interface Loopback0
 ip address 3xx.xx.68.19 255.255.255.255
 no ip route-cache cef
 no ip route-cache
 no ip mroute-cache
!
interface FastEthernet4/0
 ip address yyy.yyy.yyy.234 255.255.255.248
 no ip proxy-arp
 duplex full
!
router bgp xxxx
 no synchronization
 bgp log-neighbor-changes
 network yyy.yyy.yyy.19 mask 255.255.255.255
 neighbor yyy.yyy.yyy.233 remote-as zzz
 neighbor yyy.yyy.yyy.233 ebgp-multihop 5
 neighbor yyy.yyy.yyy.233 update-source FastEthernet4/0
 neighbor yyy.yyy.yyy.18 remote-as zzz
 neighbor yyy.yyy.yyy.18 ebgp-multihop 10
 neighbor yyy.yyy.yyy.18 update-source Loopback0
 no auto-summary

The state is Active and never changes.

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  
State/PfxRcd
yyy.yyy.yyy.233    4   zzz     144     154       11    0    0 
00:23:20       
yyy.yyy.yyy.18      4   zzz       0       0        0    0    0 never    
Active