Hi tintor and welcome,
Thanks a lot for your bug report, tintor.
We managed to reproduce the bug successfully, so it will be fixed in the next release.
In the meantime, you can use Blackvoxel in windowed mode with fixed resolution.
If you can't set the resolution in Blackvoxel, download the
Settings_Hardware.dat file and put it in the Blackvoxel data directory which is in your home. This is a text file and you can adjust the resolution as you wish.
Thanks again,
The Blackvoxel Team