David - I realize  by using Beans as an illistration -
 I did nothing toward an  answer to your concern.

The term "continous" gets confusing as  to wether
one is using Weekly continous nearby -which changes Months
or the Weekly continous single contract of say March

on Your corn -
Are You using the for the -

Normal Weekly chart - showing the Wav 3 Low on Sep 29, 2014
Tracking the ZCH16 (2016) contract  at 374.25

http://www.barchart.com/chart.php?sym=ZCH16&style=technical&template=&p=WO&d=O&sd=&ed=&size=L&log=0&t=CANDLE&v=2&g=1&evnt=1&late=1&po=1&o1=&o2=&o3=&sh=100&indicators=SMA%2855%2C%29%3BSMA%28100%2C%29%3BSMA%28200%2C%29%3BSTOSL%2814%2C3%2C16711680%2C153%29%3BSMACD%2812%2C26%2C9%2C16737792%2C10053375%2C13421721%29%3BSRSI%2814%2C6710886%2C20%2C255%2C16711680%29&chartindicator_7_code=SMA&chartindicator_7_param_0=55&chartindicator_7_param_1=&chartindicator_8_code=SMA&chartindicator_8_param_0=100&chartindicator_8_param_1=&chartindicator_9_code=SMA&chartindicator_9_param_0=200&chartindicator_9_param_1=&chartindicator_10_code=STOSL&chartindicator_10_param_0=14&chartindicator_10_param_1=3&chartindicator_10_param_2=16711680&chartindicator_10_param_3=153&chartindicator_11_code=SMACD&chartindicator_11_param_0=12&chartindicator_11_param_1=26&chartindicator_11_param_2=9&chartindicator_11_param_3=16737792&chartindicator_11_param_4=10053375&chartindicator_11_param_5=13421721&chartindicator_12_code=SRSI&chartindicator_12_param_0=14&chartindicator_12_param_1=6710886&chartindicator_12_param_2=20&chartindicator_12_param_3=255&chartindicator_12_param_4=16711680&addindicator=&submitted=1&fpage=&txtDate=

or Weekly Continuation chart - showing the Wav 3 Low on Sep 29, 2014
Tracking   the ZCH15 (2015)  at 330.5

http://www.barchart.com/chart.php?sym=ZCH16&style=technical&template=&p=WC&d=O&sd=&ed=&size=L&log=0&t=CANDLE&v=1&g=1&evnt=1&late=1&po=1&o1=&o2=&o3=&sh=100&indicators=SMA%2855%2C%29%3BSMA%28100%2C%29%3BSMA%28200%2C%29%3BSTOSL%2814%2C3%2C16711680%2C153%29%3BSMACD%2812%2C26%2C9%2C16737792%2C10053375%2C13421721%29%3BSRSI%2814%2C6710886%2C20%2C255%2C16711680%29&chartindicator_7_code=SMA&chartindicator_7_param_0=55&chartindicator_7_param_1=&chartindicator_8_code=SMA&chartindicator_8_param_0=100&chartindicator_8_param_1=&chartindicator_9_code=SMA&chartindicator_9_param_0=200&chartindicator_9_param_1=&chartindicator_10_code=STOSL&chartindicator_10_param_0=14&chartindicator_10_param_1=3&chartindicator_10_param_2=16711680&chartindicator_10_param_3=153&chartindicator_11_code=SMACD&chartindicator_11_param_0=12&chartindicator_11_param_1=26&chartindicator_11_param_2=9&chartindicator_11_param_3=16737792&chartindicator_11_param_4=10053375&chartindicator_11_param_5=13421721&chartindicator_12_code=SRSI&chartindicator_12_param_0=14&chartindicator_12_param_1=6710886&chartindicator_12_param_2=20&chartindicator_12_param_3=255&chartindicator_12_param_4=16711680&addindicator=&submitted=1&fpage=&txtDate=

or Weekly Nearest chart - - showing the Wav 3 Low on Sep 29, 2014
Tracking   ZCZ14 (Dec 2014)  at 318.25

http://www.barchart.com/chart.php?sym=ZCH16&style=technical&template=&p=WN&d=O&sd=&ed=&size=L&log=0&t=CANDLE&v=1&g=1&evnt=1&late=1&po=1&o1=&o2=&o3=&sh=100&indicators=SMA%2855%2C%29%3BSMA%28100%2C%29%3BSMA%28200%2C%29%3BSTOSL%2814%2C3%2C16711680%2C153%29%3BSMACD%2812%2C26%2C9%2C16737792%2C10053375%2C13421721%29%3BSRSI%2814%2C6710886%2C20%2C255%2C16711680%29&chartindicator_7_code=SMA&chartindicator_7_param_0=55&chartindicator_7_param_1=&chartindicator_8_code=SMA&chartindicator_8_param_0=100&chartindicator_8_param_1=&chartindicator_9_code=SMA&chartindicator_9_param_0=200&chartindicator_9_param_1=&chartindicator_10_code=STOSL&chartindicator_10_param_0=14&chartindicator_10_param_1=3&chartindicator_10_param_2=16711680&chartindicator_10_param_3=153&chartindicator_11_code=SMACD&chartindicator_11_param_0=12&chartindicator_11_param_1=26&chartindicator_11_param_2=9&chartindicator_11_param_3=16737792&chartindicator_11_param_4=10053375&chartindicator_11_param_5=13421721&chartindicator_12_code=SRSI&chartindicator_12_param_0=14&chartindicator_12_param_1=6710886&chartindicator_12_param_2=20&chartindicator_12_param_3=255&chartindicator_12_param_4=16711680&addindicator=&submitted=1&fpage=&txtDate=

I certainly dont know which is better to use,
but I can see they would cause discrepancy if mixed together

Now I have myself confused