Text (LE/9th/10): 2/4. ; Untap all permanents you control during each other player's untap step.
Other effects can prevent a permanent from untapping during an untap step. You do need to look carefully, however, as many effects say that the permanent does not untap during its controller's untap step, and this card's ability occurs during other players' untap steps. If a card does say this, then Seedborn Muse can untap it. But other abilities are not written this way and can still prevent a card from untapping, such as Storage Matrix. [D'Angelo 2003/02/16]
Some cards, such as Homarid Warrior and Spectral Bears, will not untap during a player's untap if one player uses the card and then the controller changes. The "during your next untap" means the next untap step of the player that controlled it at that time. [Barclay 2003/01/27]