HavingTrouble Losing Connection With 600m using Intel B/G wireless card

This is the problem I'm having.  When I use my 600m to access the internet wirelessly, I can view one web page and then when I try to access any other pages I get page can't be displayed.  I can't get my e-mail either.  If I reboot I am able to again bring up yahoo and access another webpage.  After displaying and surfing the webpage I am again unable to access any more webpages.  When I boot up my Inspiron 4000 using a D-link external wireless card, I can surf the net to my heart's desire with no drop in the connection or needing to reboot.  I have the Intel card manage my wireless connection.  Any ideas?

thanks for the help in advance.  It's very frustrating not being able to surf the internet wireless using my new system.  I haven't even had it a month.