Most of these scripts use the ReloadScript function created by CookieRevised in order to reload the script on demand. See
CookieRevised's reply to Restart script through code for the details.
This registry key value reflects the "Enable script debugging" setting and is needed to determine whether changing a script file would cause Plus! to relaod the script or not. Plus! only reloads a script when debugging is enabled or when the script debugging window is opened.
To fix this issue, these scripts would have to add a Plus! version check and use "HKEY_CURRENT_USER\Software\Yuna Software\Messenger Plus!\Windows Live Messenger\GlobalSettings\Scripts\ScriptEnableDebug" for Plus! 5 instead. However, I don't think I'd change Countdown Live just for this as it shows a dialog box when the script couldn't be reloaded automatically. I'll probably add it in a later update...
Still, it appears that Video Converter Plus! also writes to this value, it looks like it's trying to force debugging to be enabled. You might want to contact the creator about this so he can evaluate the consequences and decide whether an update is necessary.
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