Cryptic postings lacking full information are more difficult to solve. Are you running 11.5.1.2266? If not, you need to update to this version for use with Win 7.
Also, if your machine is not getting an IP address then it is highly likely that you do not have the correct Vista 32 bit drivers for your NIC. (Vista 32 bit drivers are required for WinPE, regardless of the operating system being imaged)