Please don't use M$ terms, they might sue us

(seriously, I'm not sure whether Intellisense is a registered trademark or not, but better be safe and cool, use our own term).
There are at least two cases where codetools will fail:
- Broken cache, can be fixed by what Martin says
- Syntax error at important points, that is, points required by codetools to do its job
So ensure both, and codetools will work fine again.