For vmail, the old trick might work -- call your Z10 number from a different line, don't answer and leave a message. Then retrieve/delete the message on the Z10. Sometimes that kicks the carrier notification system and clears things up.
As for your email timestamp issue...if you mean the sending timestamp, no news there...but we are all hopeful regarding future OS updates.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.