Stephan J. Turnbull wrote: Uwe> According to Christoph Wedler to whom I sent the backtrace Uwe> the curprit is xemacs, not x-symbol. I don't bind `command-history', but `values'... arg! I looked at `truncate-command-history-for-gc' just briefly and never thought that values is not a local variable (it's not), but a global variable (not a good idea!)... OK, I'll fix X-Symbol that it never ever uses a local variable `values'. I think quite a few other packages / functions will have to do the same: e.g., `widget-item-match-inline', `widget-choice-match-inline', and other widget function all have parameters called `values' whose values do not have to be lists. Since garbarge collection can occur almost ever, XEmacs already has a huge list of potential problems... A safer alternative would be not to change `values' during any function in `pre-gc-hook' or better: rename this global variable `values'. - Christoph