From these forums it seems as though many people are having problems with the wireless function of the DG834G. It either hangs or the router crashes, requiring a reboot, only for the problem to occur again.
A major cause of this, is using a peer-to-peer client. But do not worry, there is solution to this.
With most P2P clients, you will need to forward ports using the router for them to work properly. The major problem here is that when ports are forwarded, the default setting is to "always log". This has to be changed to "never", as the router can not handle logging all the connections, causing it to crash.
Also some clients like emule have a default setting of "20 connections every 5 seconds". This will also cause the router to crash and needs to be changed to "5 connections every 5 seconds".
As you can see, trying to log 20 connections every 5 seconds can be a strain for most routers, but especially the DG834G.
I hope this helps to solve some of your problems.
P.S. I use firmware version 1.03.07 for my DG834G.