Script editor slows down

[wildweasel]

I'm running Doom Builder on a Windows XP machine (SP1), Pentium 4 3.0 Ghz with hyperthreading and 512 MB of RAM. When I edit an ACS script with the built-in script editor, everything seems fine, until the editor has to scroll from side to side while I'm typing. This makes it slow down to where it's only typing 3 characters per second. I don't know what exactly is causing this - I've closed all open programs and even disabled theming support on Doom Builder itself.