wireless connection won't resume after sleep

> Dell E1505 laptop
> Router firmware upgraded
> All drivers most up-to-date versions
> Vista completely up-to-date
>
> The computer has "limited only connection" after resuming from sleep, and
> either won't reconnect at all, or else takes a very long time to reconnect
> (15-20 min.)
>
> I am aware this is a common problem and I would like to know if there is a
> solution for it yet.
>
> -I have tired the "power management" solution setting for the wireless
> card.
> -I have tried disabling IPV6
>
> using "ipconfig/release -> renew" sometimes gets me back online (but
> usually
> not)
> using "Diagnose and repair" sometimes gets me back online (but usually
> not)
> Rebooting almost always works, but is very annoying.
>
> The only solution I have been able to come up with is to never use sleep
> or
> close the laptop without shutting down first - which seems to me like a
> significant loss of functionality compared to XP.