3 or 4 parts to your problem.
A – Verify that the information on the DNS tab of ‘Advanced TCP/IP properties’ is correct – i.e. append primary and connect specific info is selected AND depending on your DHCP setup the DNS specific box is not blank. [Right-Click ‘Network Places’ select ‘Properties’. Right-Click ‘Local Area Connection’ select ‘Properties’. Select Internet Protocol (TCP/IP) and click ‘Properties’]
B – mshome.net is a default for Microsoft’s wireless router setup. Either there is a rogue ‘Wireless Access Point’ or you left the defaults when it was installed. Then XP, when signing on to the network, takes info from the WAP instead of the DHCP server.
C – Much like the auto-configuration IP address 169.xxx.yyy.zzz when you first setup a computer the business of mshome.net is ‘helpful’ defaults. Your problem is the help interferes with normal operations.
IF the WAP is authorized then replace the defaults as appropriate. If it is a rogue – search and destroy.