It looks like when you're banned by a user you can't comment on their hub entries, but it's not made clear why. Things just lack the "add post" button making it seem like the site is broken. I wouldn't be surprised if it had the same behavior for non-members who can't post on some member-only things (if that restriction still exists). This is further complicated by not being able to post on things in BYOND's forum that are related to hub entries you can't post on because it's not obvious that BYOND's forum's content is actually the aggregation of hub entries.
Numbered Steps to Reproduce Problem:
Code Snippet (if applicable) to Reproduce Problem:
Does the problem occur:
Every time? Or how often?
In other games?
In other user accounts?
On other computers?
When does the problem NOT occur?
Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)