Fabric Bend Sensor - Auto-Regulating after five minutes?

I made my own fabric bend sensors using Neoprene, Velostat (an anti-static plastic sheet that has natural resistance) and conductive fabric/thread. (I worked off of this tutorial: http://www.instructables.com/id/Fabric-bend-sensor/#intro), and I noticed something odd. Each time I connect the sensor to my arduino for the first time (I am working with the Uno) it gives weird, noisy data (all over the place, the numbers I get range from 10s/20s to 1000 regardless of whether I am touching the sensor) for about five minutes before it slowly adjusts itself, coming down to zero when it is not touched, and about 10-20 when being pressed or bent (this is how it is supposed to work). After that it works fine. I can't figure out why it appears broken for the first five minutes before adjusting itself. Is there some kind of function built within the Arduino that I am not aware of that would cause this to happen, or has anyone else experienced this with sensors?

Just trying to figure out what is happening so I don't mistakenly sew some broken sensors into my wearable.

Thanks!

There is no built in function in the arduino which would explain such a behavior.

You get the type of noise which you describe if you do analogRed() from a pin which is not connected to anything.

How are you connecting the sensor? If you tell me how the sensor is connected I could think about it some more.