Not, actually. One needs to have mature coins (not reserved) in order to stake. If you've got any available coins in your wallet, simply wait for them to mature and stake.

Yesterday my wallet have been staking fine. But I noticed this morning that my wallet was falling out of sync every time it received uncorfirmed stake coins. As a result, when It synced the blocks again, the recently staked coins were lost (with a "?" sign, instead of the small clock sign or the green tick sign). What I have done to solve this issue was deleting the entire warp's blockchain files (at appdata) and resyncing it all from zero (it's pretty quick). Now it is staking normally again.