Regarding "Warning:  error: no space left in stack for back_add" pproblems with
recent httrak releases

The bug should be fixed in 3.41-beta-3 (3.41.8), at last.

The cause:

Error files (404, ..) and html files are not immediately processed in
background by httrack once downloaded, but rather put in "wait state" until
the engine checks them.

Background files in wait state" are stored temporarily on disk, to spare
memory, and not to fill the back table.

A bug was causing this temporary file no to be checked for directory
consistency (that is, the engine did not check if intermediate directory
existed), thus not always allowing the engine to cleanup the background stack
properly, leading to fill the table after a while.

The other problem was the lack of error report on the logs while failing to
create this intermediate file (shame on me!), and it explains why it took so
much time to find this very very annoying bug.

Please download the latest beta version if you encountered this bug.