After several months of testing, several new releases of Hyper Estraier with new features (newest one is masking [excluding] of linked databases when searching) version 0.07 is finally ready.
I would really suggest to all current users to upgrade to latest version. It fixes problems with set_skip and vectors and has, well, set_mask.
Require explicit version of this module when using new features, just to be safe that you are not running against older version (it's only sane behavior).