VoIP Phone and Wireless internet stopped functioning simultaneously

I have recently purchased an IP phone (Linksys IP Phone SPA942) and Linksys Wireless G Router. I use my internet connection (From ISP to ADSL Broadband Router and then broadband router to Linksys Wireless G Router and then to my Dell Inspiron 700 M Wirelessly) on my laptop to access the internet.

Yesterday from my ISP some techie has come and changed the DNS Server and alternate DNS Server addresses leaving the IP as same and some modifications which I actually dont know.

Unfortunately, after those changes I am not getting internet connection from my Linksys Wireless G Router to my Dell Inspiron Laptop. If I remove the internet Cable from the wireless G Router and put it into my laptops port, I am getting internet but losing connection to my VoIP phone.

It was not the case earlier. When I asked the techie, he mentioned that as the equipment (Wireless G Router and VoIP Phone) was not supplied by them so that he wouldnt touch.

Which setting should be verified and What changes should be made to my laptop, Router and VoIP in order to get my data and voice both functions are done simultaneously.

Thanks in advance