Unless I'm doing something wrong there appears to be a bug in the positioning of the vertical trackbar where a vertical trackbar is displaced to the right at runtime compared to its position at design time.
An image showing the two views can be found at:
To reproduce, create a new web core project, place a web trackbar on form, change to vertical orientation and place any other control next to the trackbar as a reference point. Run code, trackbar will have moved to the right.