The workaround is to change it to shorter. These are not PCs, they don't run Windows and there are no drivers to tinker with.
This limit is on other makes as well.
Bob
I am trying to connect my 42LM6200 to my wireless network, but when I try to enter my wifi password on the TV, it seems to only allow 32 characters - it appears to stop adding asterisks to the input line. This is a problem because my wireless password is 63 characters long.
We have several computers, a printer, an iPod, an iPad, a Roku, a Tivo, all conncted to this wirless network, all allow 63 character password input.
Is this a known problem, or is there a workaround?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic