It's a bit difficult to help you when you just keep ranting "Leopard sucks" and all you post is that you use a 2Wire router (especially since 2Wire doesn't maker stand-alone routers -- I assume you mean 2Wire's router/modem combo?).
I don't really get it when they said that it fixed wireless problems, because it caused a lot more!
I take it from this that your problem started *after* you upgraded to 10.5.2? Otherwise, what "a lot more" problems are you experiencing?
Tell us more about your setup and what you have tried that hasn't worked, and you will probably get a lot more helpful suggestions. In particular, it would be helpful to know things like:
* what sort of network security are you using, if any?
* do you have any other wireless devices connected to the network, e.g. a printer or an iPhone, and do those devices drop the connection also?
* where is the 2Wire located in relation to your Mac?
* are there any wired devices on the network? Do they have issues?
* what Mac do you have?
* have you created a new user account on your Mac and does the problem happen there as well?
* what third party software have you added that might impact a wireless connection?
* have you tried all of the "first steps" type of stuff, eg repairing permissions, resetting the PMU, etc.
* how far is your closest Genius Bar?
Are there any threads on MR or Apple Support in which others report experiencing your problem, and what have they tried that didn't work?
I know it is frustrating, but keep in mind that legions of us are using 10.5.2 with no wireless problems, so, it isn't the case that 10.5.2 is the "worst update ever" or is causing widespread wireless problems. There is something going on with your system that is causing the problem. If you can remain calm (think Kevin Bacon...), you are much more likely to get some help.
On the other hand, if you don't want the help and just want to rant about 10.5.2, hey, go for it.