Does Shavuot always falls on the first day of the week

[Havah]

Some have already known this is Karaite doctrine.
Leviticus
23:15 until the seventh day after the Sabbath, count fifty days; new offering sacrifice to the Lord.
(I used star21 to make such translation)

The Omer 49 used in current mainstream Jewish calendar was not always fall on Shabbath. <!-- s --><img src="{SMILIES_PATH}/sad.gif" alt="" title="Sad" /><!-- s -->

Of course I know some people adhere to this Karaite doctrine.
But recently I found they switched back to Pharisaic doctrine. <!-- s --><img src="{SMILIES_PATH}/sad.gif" alt="" title="Sad" /><!-- s -->

Which one is true?