Bingo! 2 ** 16 works fine

BTW, the UI is a lot more usable when you'd change all ->pack; to ->pack (-expand => 1, -fill => "both");

Some suggestions:

• (auto) color user names
• time stamps
• align start of text (fixed width for user names)
• search box
• log all conversation
• auto-color code sections
• an option to use mono font for code sections and variable width font for "normal" conversations (*I* would NOT use that, but I know people who'd love that