"tput clear"/vi breakage on console

Hi,

It seems "tput clear" on console wipes out entire screen without
even showing a shell prompt. The only way I get characters is to
enter "enter" key. I'm under the impression that the first line of
console output is not displayed at all after "tput clear" command.
Another thing I noticed is vi also does not show the first line
of a file. Any idea?