airport express cuts out

My airport express will play iTunes for about 20 secs and then it starts to cut out. Nothing new in the house. I tried changing ports, rewiring the area around it, updating firmware, shutting off all phones that are wireless.
I can't seem to down load the update that supposedly fixes the problem since I can only be on the net or the express and the website apparently downloads straight to the express.
Any ideas?

I was successful in adding the Airport Express to my Vonage adaptor and the cable modem, and my laptop is now wireless. What are the concerns regarding network security while wireless? Thank you.