Depending on the relevance of the post that you use to bump the thread and the relevance of the thread itself. It probably varies(infraction or not) depending on its worth.
I wouldn't recommend doing it, because most old thread bumps are either outdated and or irrelevant.
For example, I doubt administration would infract someone for adding helpful information to an old tutorial thread.
Even still, its probably better to just make a new thread, possibly stating Added to [Name's] Previous Thread, or something along those lines.
Last edited by Muur; Nov 21, 2011 at 05:32 AM.