My wireless router offers both 2.4 GHz and 5 GHz bands. I'm using the 2.4 GHz band exclusively with my Pronto remotes, the Security Mode set to WEP128. Haven't experiencing any issues until very recently. It was happening with all my remotes.

I'd send a command and it would fail to execute. The busy indicator light on the first extender involved would light up and stay that way clearing after an extended period of time. If I sent the same command subsequent times it would eventually work, the busy indicator light then clearing. Ended up just having to reboot my router. Been smooth sailing ever since.