I know that it annoys me too but as I've said that already, I'm using 3rd party highlighter library which has some annoying bugs. The author of this library has been inactive for ages and I'm not going to fix it any time soon. I want to get rid of all the bugs not related to syntax highlighter first and then, maybe, I'll try to use different library which someone suggested in this topic.
I'd suggest not to use "function" word in function name. Use "Func" instead, like "callClientFunc", that's what I do. I'm not sure maybe I made a mistake in lua.syn file which messes up. If I did messed up and someone found a fix for this then please post lua.syn file here so others can use it too. Thanks.
BTW, I must admit, MTA:SE seems to be so much stable now than it used to be. I don't receive bug reports (crash reports) very often, in fact I haven't received any for 3 days now (I used to get 3-4 a day!).
I really want to get this tool "bug free" but college takes most of my spare time.