No lyrics No way to play video clips with display off-iOS 4.3.1. iPhone

Hi,
since Ive did my last update, iOS 4.3.1.,got two problems about playing videos.
1. Can not get the lyrics on the display while playing the videos, when you click on the display, it shows time only but no lyrics, if I play normal song (any format) its all fine !
2. If I want to play videos and turn off the display, I just can do it, button play just do nothing, it want let me to play that videos and again if I play normal songs, its all fine !
Interesting is, it was all good before this update,Do you guys have a same problem with 4,3.1. what we can do about this?
thanx
iphone 4 iOS 4