I can also now fully confirm from my several days' worth of observations that the problem is fixed. Excellent!
Just be aware 4.18 can not be put on all Vue consoles, only those with Mfg codes of MB or higher
My Vue console has a manufacturing code that begins with an "E" (purchased during September of 2011), but the firmware update nevertheless did work and the current firmware version shown on the console in setup mode is indeed 4.18. That said -- both my Vue console and the datalogger attached to it are pre-green dot, and an irregularity appears to have arisen since I updated the firmware: the console can still communicate with a computer in real time (i.e., feeding the "Bulletin" page on WeatherLink, or running WxSolution or any other weather station software), but it does not appear to be able to log any archived data to download in WeatherLink. When I try to download the datalogger in WL, I simply get the "no new data to download" message. Thankfully, I don't need to use this datalogger -- it's an old spare -- and I just use the Vue console for viewing purposes. But this is something to consider for anyone else using pre-green dot Vue consoles and dataloggers and seeking to upgrade their console firmware.
I'll continue to try downloading the datalogger in WL and will report back if the problem resolves itself.