Ok, this explains a lot. Titans kernel got installed because mobilehotspot depends on kernel-feature-netfilter (which titans kernel provides). Reinstall stock kernel and you should be good to go (uninstalling just mobilehotspot will not uninstall titans kernel and I'm not 100% titans kernel automatically reflashes stock kernel after uninstall [which would be kinda smart to do]).

I kinda suppose (yes, supposion is the mother of all f*ckups) that people testing stuff from extras-devel seeing the package description (where it's stated that a custom kernel is required and might be installed automatically) know what it means.

edit: Do you mean reflashing stock kernel made no difference to Joikuspot ? Interesting but can't really help with that.