From the [`Ask Ubuntu FAQ`](http://askubuntu.com/faq) page:

> We welcome questions about:

>   - Using and administering Ubuntu, including official Ubuntu derivatives.
    - Running third-party applications on Ubuntu.
    - Development on Ubuntu.
    - Services provided by Ubuntu
    - Any question not mentioned below or here are great! There are no "dumb" questions!

What are custom kernels? Can't I compile my own kernel and use it in Ubuntu, is that not considered usage of Ubuntu?  
What if I needed to develop something that has no support while using the default kernel? Does that no follow the development line?
What if it's coming from a PPA? There can be a lot of issues simply solved by reverting to official packages, shall we ban questions that involve PPAs?  
What about if I compiled the package from source and the features changed? (ie: not an issue, just something different)

If the problem is to be solved using a standard kernel, then great, we can further try to solve it and help knowing that fact, if it can't even be connect to a custom kernel, then ignore that fact. That single fact that an user is using a custom kernel should not make a post OT on this site.