Poor bridged networking performance

[baseliner]

Hi - I'm running OS X 10.6 (Snow Leopard) host and a Win7 Ultimate 32-bit guest. The network performance in the guest is really poor - my download and upload speeds are reduced by around 80%.. I've tried all possible adapters (4 of them) available with the bridged option and some are faster than others but none come anywhere near my native speed.. NAT doesn't work for me since I need to have access to other machines on the network and vice-versa (need an IP address on the same domain as my other machines). Can this be fixed? Thanks!