4069 Inverter -problem

Hey fellows, I just used a 4069 for the first time in one of my circuits. I have a little problem, and wonder if its the nature of the chip. When I send a high to one of the inputs, it not only makes the output low, but it makes ALL the rest of the IC's outputs low.

A simulation in Yenka proves this shouldnt be so. Can anyone clarify?

Thanks

Unless you tie the unused inputs high or low they will get influenced by any capacitive coupling or simply oscillate.

Mike.

Thanks Pommie

I am using only two of the six inverters. When input 1 is made high, it will send its output to low, and also output 2 to low. Am I needing a 10k resistor between input 1 and ground, between input 2 and ground, and then simply ground the unused inputs?

Edit: The 10k resistors did the trick. Thanks for the tip!