Windows – Nokia 5800 v50, getting “Invalid server name” with ad-hoc wlan with Windows 7

After upgrading to v50 firmware in my Nokia 5800 xpress music phone.

I am not able to connect to ad-hoc wlan network in my laptop(Windows 7 OS).

I have a dialup internet connection and created wireless ad-hoc network to access the internet in my phone. But I am getting "invalid server name" in the phone and my wireless network access type in Windows 7 shows "no internet access".

I am able to connect to wlan infrastructure network using 5800 in my office. So my phone is working with wlan and I m able to access internet on it. BUT The problem is "dial up with ICS enabled" and "AD-HOC wlan network" in Windows 7.

Can anyone give some solution on it. Or can you provide a guide/tutorial to connect 5800 with adhoc network and dialup internet in Windows 7.

System:
Windows 7
Dial up internet connection with ICS enabled.
Ad-Hoc wireless network with WEP
Nokia 5800 Xpress Music phone

Note: I have read other posts also and tried their solutions but didn't worked for me. the first solution is to bridge the network and access it. but how can I bridge the dialup and wlan netwok?
second solution is manually configure IP and DNS addresses in phone. But what should I add as IP and DNS as my dial up and adhoc network have automatic addresses.