Not strictly a bug, but a UX hangup.
Point-of-view story:
Each time I leveled-up today, an in-client dialog told me I had a skill point to spend, then gave me a button to press to "spend it now", but on click, the dialog went away and I noticed no other change, so I just kept on playing skill-less until level 3, when I asked about it in chat. Someone pointed out I could access the skill-purchasing interface through my profile, and I luckily already knew I could click the Forums button to get there with only one more subsequent click.
Explanations/Suggestions:
1. My pop-up blocker (Chrome/Mac) kept me from seeing the interface for spending those skill points. Since pop-up blockers are so often on by default these days, it's probably worth detecting these scenarios where the user isn't seeing your pop-up.
2. It seemed unintuitive to me that there wasn't a link to my profile from the game interface, and instead I had to click Forums, followed by the profile link. Was I missing something?