Ya know, good question. Its going to take me a while to scour through Youtube to find any, but I'll definitely keep posted.
[edit] Went through some youtube links, I haven't found any that were using non-alphanumeric characters other than the underscore _ - but that worked fine as I tested a couple different links with that. I think Google hasn't started on those yet, so everything is working good so far.
[edit2] I broke it again. XD - [14:01:29] Tcl error [youtubesurl]: invalid command name "HD-720p" :: The title of the video is [HD-720p]DD ED, I thought it was the underscore, but it wasn't.
Ok, I think I found what's causing that youtubeid error. If I post any link that contains a hypen as the ID of the video, it'll spit that error out. If I post a video that doesn't contain such a character, it'll work fine. So, the link in my last comment would work as a test, or I have several others that would suffice as a good test ground. But each link that contained a hyphen would cause the error, and each link that had only letters and numbers would work fine.
At first the script didn't want to do anything, after spamming my test channel, it finally decided to cooperate. It appears to be working fine, testing out various youtube links in my favorites that has both unicode and other odd characters. I'll keep testing every so often and see if I can find a way to break it again somehow. XD It did spit this out in the partyline though:
Tcl error [youtubesurl]: can't read "youtubeid": no such variable
That was when I posted this: http://www.youtube.com/watch?v=-KJOC0JBDt4 - it later decided to report it properly, so I dunno.
Nice script, using it myself right now. Just one tiny problem, and this has been encountered with an mIRC script too someone coded/uses. Though it works fine with unicode and japanese characters, but it seems to show the HTML code on certain characters such as ' (apostrophe). There's probably others, but I'd have to find a way to test every character or something. XD