Yes you are correct.
RO/DI should have a S.G. of 1.00
What temperature is your RO/DI water sample by the way - just curious.
You may want to consider looking into getting a new hydrometer, or have it tested against a better known source.
These types of hydrometers are not the most precise devices in the world, but they work fine for most people.
Here's MORE than you ever wanted to know about these units
<a href="http://www.epinions.com/content_44790222468" target="_blank">http://www.epinions.com/content_44790222468</a>
Later