It’s not you, it’s the microphone.
After being annoyed by the ‘Shaky Arrow Glitch’ on Rock Band 3, I did some experimentation. It turns out that it’s not a software problem; my Rock Band 2 microphone is just crappin’ out. Fortunately, I have an alternate solution, using the Rocksmith guitar cable to take the output from my studio recorder and send it to the PS3. (I’ll look into getting an XLR-to-USB cable sometime, but right now I don’t really need it, so no rush.)
So if you’ve been playing Rock Band at my house and you thought your vocal performance was kinda crap, don’t worry, it wasn’t (necessarily) you.
So, from my Rock Band equipment, I don’t use the stock drums anymore, the stock mic has issues, one of my guitars seems to lose notes, and the other is totally erratic with Overdrive. I guess the manufacturing wasn’t perfect.
I should keep my eyes out for a higher-quality Rock Band guitar. I have the Pro Guitar, but I still need a good guitar for the standard modes.