I have my config set to sell 25% of my eth stash (let's say for the example: 2 ether) when a tweet matches a pattern. The first time it matched a tweet, it sold 25% of the stash: 0.5 ether. Stash value should be now 1,5 ether. Which is good. The next time it matched a tweet to sell, it tried to sell the same amount. Again 0.50 ether. That's not 25% of 1,5 ether. It should have been .375 ether.
Which led me thinking: is the account available correctly calculated each time an order is placed?