Sometimes when scrolling a page, some text lines are not redrawn properly. It looks as if one line of pixels is missing. It seems to happen only within paragraphs with line-height set to something other than normal. I am using Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.0+) Gecko/20020514. This was also the problem in the April 18th build.
To experience the problems you have to scroll using the arrow keys or the arrows on the scrollbar (i.e. not PgUp/PgDn or the scrollbar thumb). If the window is covered by another window and then brought to top again, the text lines are drawn correctly. Notice that the problem does not occur when line height is not specified, or when the specified height is the same as when no height is specified (i.e. 11px when font size is 10px, and 13px when font size is 11px or 12 px). The problem occurs on quite a lot of sites, so I'm setting severity to 'major'.
Hmm, appearently it is not only on text that has line-height specified. Steps to reproduce: 1. Open http://linuxtoday.com/news_story.php3?ltsn=2002-05-20-006-26-IN-LF-PB 2. Press down arrow key (or hold it pressed) until the subheader "Peruvian Bill Number 1609, Free Software in Public Administration" scrolls into view. The whole following subsection is drawn improperly. From the subheader "Writing the Letter" and to the end of the page everything is right again, i.e. the problem only occurs between those to subheaders.
Changing QA contact to Moied
This is almost certainly a twips rounding problem.
*** This bug has been marked as a duplicate of 80530 ***