Same situation here.

Today repaired a miner that had a faulty blade and it's now mining OK according to the status page on the miner.
However Slush reports 0.0 Mh/s even after waiting 30 - 60 minutes. I would expect to see a slow increase in Mh/s during the first hour of mining.

Seems to be something wrong on Slush side. Just hope my shares won't be lost. It's about time this S3 is generating some revenues after arriving as DOA-unit.
[Great service from Bitmaintech to swap out the faulty board by UPS within a week]

BTW my other miners report the right stats on Slush only the re-attached S3 miner is showing 0.0.

EDIT: after regular checks it seems the Mhash/sec are currently not being updated on the website. My android app is showing that my miners are all working normally and with expected hashrates. Also payout seems consistent so no need to worry about that.