Connecting switches/pots to PSoC

[gokul]

We have managed to hook up a rotary switch, a SPST switch and a 100K pot to the PSoC kit, using one of the breakout boards available now.

The switches are working fine and their states can be seen in the Driver Station (inside the I/O tab) but the Analog Input has an odd behavior.

When nothing is connected on the AI lines, the voltage as reported by the Driver Station is jittery but around the max 3.3 range for each of the AIs.

When I connect one 100K Lin pot to AI 01, that input stays rock steady and moves correctly to 3.3V without jitters.

Oddly the other AIs (2,3,4) that are not connected and are floating, also follow the AI 01 - when the pot is changed!

Why would this be the case?
What should be the teams doing ? Tie the unused AIs to ground ? Of course one should not be checking the unused ones in the software but what would be the safest solution ?

Please advise.