Maximum bit level is not obeyed when getting TF work

[kruoli]

I used the --max-bit option to limit TF work. Let's say I wanted to go from $2^x$ to $2^{x+1}$. Neither setting it to $x$ nor to $x+1$ worked and I got other ($2^{x+1}$ to $2^{x+2}$). The version I downloaded was around an hour ago from mersenne.ca. Is it strictly necessary to also set --min-bit?