Because of this issue with the nicehash API I have decided to update the bot to cancel and relist orders. I emailed NiceHash but they wont raise the the limit on how much you can decrease your bid price.
Because the decrease price function in the API only decreases the order price by such a very small amount, it is necessary to cancel and relist the order when it is mining at a cost above the max price you are currently willing to pay. The downside to this is that a small fee is incurred to relist (currently 0.0001 BTC) therefore care should be taken to monitor how often orders are being relisted by the bot by viewing the order history (https://www.nicehash.com/index.jsp?p=horders).
You can see the code changes here:
https://github.com/KittyCatTech/bipcoin-nicehash-bot/commit/27a3be31edb3a905d73fdbf71414da6d757ad619
Main link to the github:
https://github.com/KittyCatTech/bipcoin-nicehash-bot
Added on BipCot.org to list of things license BipCot NoGov license.
http://bipcot.org/?p=1107