What's the concentration of your salt solution? But, regardless... this is what generally should happen, if I'm not mistaken. Hurrah, osmosis! (Heh.)
Boiling the potato strip for 10 minutes means that you're basically immersing it in water, which as we all know is hypotonic to potato strip cell sap. This means it'll become firm and absorb the water, with the rate of water entering the cells of the potato strip being higher than the rate of the potato strip's cell sap diffusing out of the cell and into the boiling water.
Now, salt solutions are hypertonic to the potato strip's cell sap. After you're done boiling that poor potato strip and you place it inside the salt solution, the potato strip'll become flaccid. The water molecules inside the cell sap diffuses out into the salt solution at a higher rate than the rate of the water molecules of the salt solution diffusing into the cell sap inside the cells of the potato strip.
Aaaaaaand you also get a salty potato strip, if that helps. ;) If anything, the heat/temperature of the potato strip should encourage the absorption of the salt solution by the potato strip, so... I'm also assuming that boiling the strip for 10 minutes rather than just placing it in water of room temperature was to speed up the osmosis reaction of the potato strip towards the water, but... I don't know about that. 8D Eheh.
Edit: I knew I missed something! Do refer to the answer below to find out what happens to the membranes of the potato strip when you boil it. It's quite crucial.
My Biology classes, from... a long time ago. 2 years, actually, when I was learning about osmosis. *is actually a pre-engineering student, at the moment*