strange connection problem help needed please

i have a wierd connection problem on my laptop , i use an nb3 router and up until yesterday it was fine then all of a sudden it stopped me connecting to the net via explorer and mozilla and also outlook express, but and this is the weird thing it still allows soulseek to connect???????

so i tried another modem a d-link 200 and it has let me connect again?

i went back to the nb3 and it still only lets me connect to soulseek , what could have happened or changed within the nb3 to do this ,i havent changed any settings?

also when i tried to change my ports to open for soulseek i successfully did it , now its saying the port is closed again? when it says you must restart your client what is my client?