Kernel panics/crashes in 40, no problems in 80

I just came across this weird issue with Supra. When running it in 40 column mode those frightening RS-232 breaks appear in BBS Telnet Server and nuke the BBS throwing into a monitor. However these do not appear at all in 80 column mode.

I prefer 80 column mode but I realize that most users are going to be using 40 column mode. Still, it would be nice to figure out what the magic issue is here. Please share your thoughts in the comments or in the forums.