Uninstall FFD filters, and any codec pack that might have them pre-installed (CCCP).
Rather than uninstalling them, which I don't recommend, they should be able to add an exception for the Fallout New Vegas and Fallout New Vegas Launcher .exe files. I did this (I'm using the k-lite codec pack) and it fixed my audio problems.
It's quite possible this may happen because the prison changes hands to the NCR once you start the assault, rather than after.
Nope, this has happened to me at Powder Ganger hideouts and I haven't even found the prison yet.
A couple notes regarding my recent bugs: the blue tint effect seems to be the Cateye effect (I just took my first dose and it was identical to the bug). Since there's no message that it's wearing off when the bugged version wears off and I haven't gotten addicted or anything, I'm assuming it's not triggering the full effect, just the visuals.
Also, Rex attacked a quest-related NPC (after I'd finished talking to him), so I sent him to the Lucky 38 until I can figure out what's going on or the bug is fixed. If it's a bug at all - maybe I should have stuck with the old lady's dog.