XFire is known to cause problems with some routers. DSL disconnects, high latencies, reboots. I am mobile right now and don ot have the link. The developers created a list with affected models in their forum.
Since I started playing here my friends list was growing and some day my router started to reboot sporadically when I opened XFire. The client opens many connections and some cheaper routers are not able to handle them. I solved it with a new router but I didn't buy it because I had probs with XFire. Needed an upgrade to n-draft W-LAN
Try Pidgin with the Gfire plugin
Download Pidgin: http://www.pidgin.im/download
Download GFire: http://gfireproject.org/download
But don't expect too much. This plugin only provides the base functions. No video recording, no broadcast, no screenshots, no overlay, no voice chat etc..
You can chat, see who is playing, transfer files and I think the game detection works too.
But i am not sure about the last two things. I use pidgin on Linux only. I'll add a screenshot when I am at my desk.