In Lily's birthday, the cake was near the stage. When Oliver blows it up, Billy Ray is near the shake bar that was far from the stage, but still they got hit with the cake's explosion.
When Bobby Ray is collecting the dishes at Grandma's party, he has 2 handfuls of dirty dishes with silverware and napkins on each one of them. But when he shakes Lorelai's hand he only has 4-5 plates, which appear to be clean and without the napkins and silverware.
Immediately after the first verse of song Hoedown Throwdown, Miley picks up the mic from the stand with her right hand, then within two seconds the mic is placed on the stand and not in her right hand.
At the concert in Tennessee, the shadows keep changing from long to short.
Miley gets her luggage out of the truck with her beauty kit is in her left and her dress is in her right. Miley stops and faces her father. Then her luggage was inverted. But if you look and observe closely, the camera turns with Miley and the luggage is not moved.
When Miley dressed as Hannah is talking to Travis outside the house, her real brown hair is noticeably visible through the wig.
Near the start, when Hannah's publicity manager is on the beach, she is shown typing on her computer but the screen is blank.
Near the beginning when Miley is leaving gym class and stops at her locker you can see her pull it open a little and the fiddles with the lock, as it unlocking it. But if it was really locked to begin with it wouldn't have opened at all.
The town in Tennessee is supposed to be a quiet little farm town. They filmed the main street scene in Columbia, TN, a city of over 33,000 people. If you look carefully in the background you can see a busy highway or boulevard most likely used by commuters going to Nashville.
Everytime Miley takes off her wig, her hair is in a messy knot at the back of her head. If her hair was really like that it would be noticeable through the wig.
When Hannah is giving away free watermelon samples she says, "Here you go girls." But there is only one girl there.
When Lily is pretending to be Hannah in Miley's bedroom, Miley says Hannah can only fly west to east, so she has to take the long way. Flying directly from Los Angeles to Tennessee IS flying west to east.
Miley proceeded to sing Hoedown Throwdown at the party and the people don't recognize her voice as Hannah Montana.