You've probably found a bug in lesstif.

Fujie Zhang writes:
> i'm using lesstif 0.82. i occasionally came accross this problem of
> having all the opened X based program windows frozen. in other words, i
> could not move, iconify, resize, bring forward/backward, and thing like
> those. i notice this happens if i don't move any window for a while.
> does lesstif goes to sleep after certain period fo no activity? help
> appreciated.
>