I have the G500, couldn't be happier. Best mouse I have owned.
Is it a double clicking issue?... if so, Razer has firmware patches that revived my Copperhead.
If it is dead-dead, SnW mentioned Logitech's MX518, which is my desktop mouse are a bargain now. For GBP45, I'm eyeing (sp?) their G500 for the dual mode scrolling wheel, better button placement and onboard memory. Even if Logitech still lack the ultra convenient, dedicated profile switching button.