I have a windows 7 host with firewall turned off. And I have a windowsXP guest running on Virtualbox 4.2.4r81684. In my windowsXP guest I tried to connect to the FTP server on my host machine(which used to work well) but it didn't work. I tried to ping my host machine, but it didn't work either. Then I tried to ping my guest from host, it worked well.

my guest ip is :192.168.1.95
my host ip is : 192.168.1.9
route table on guest machine is this:

C:\Documents and Settings\wenlong>route PRINT
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...08 00 27 66 54 6c ...... AMD PCNET Family PCI Ethernet Adapter #2 - Packe
t Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1    192.168.1.95       20
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
      192.168.1.0    255.255.255.0     192.168.1.95    192.168.1.95       20
     192.168.1.95  255.255.255.255        127.0.0.1       127.0.0.1       20
    192.168.1.255  255.255.255.255     192.168.1.95    192.168.1.95       20
        224.0.0.0        240.0.0.0     192.168.1.95    192.168.1.95       20
  255.255.255.255  255.255.255.255     192.168.1.95    192.168.1.95       1
Default Gateway:       192.168.1.1
===========================================================================
Persistent Routes:
  None

arp cache is this:

C:\Documents and Settings\wenlong>arp -a  
Interface: 192.168.1.95 --- 0x2  
  Internet Address      Physical Address      Type  
  192.168.1.1           00-26-f2-60-3c-04     dynamic  
  192.168.1.9           90-e6-ba-c2-90-2f     dynamic  

It's strange because there was no problem days before and I didn't make any changes to the setting. could anybody help?

PS. the guest can communicate with other machines in the LAN(for example 192.168.1.114) ok. it just cannot connect to the host machine.