What versions of WordPress and Geo Mashup are you using?
WP 2.7.1 - GM 1.2.5

For problems, describe the problem and provide a URL where the problem is
happening.

1/ show_future doesn't work if map open from category-n using :
echo
GeoMashup::map('height=300&width=620&zoom=9&add_overview_control=true&add_map_type_control=true&auto_info_open=false&show_future="true"');
}?>

It does from global page or post using :
[geo_mashup_map height="200" width="400" zoom="2"
add_overview_control="false" add_map_type_control="true" show_future="true"]

2/ But, from global page ([geo_mashup_map] + global show_future option
checked), it does display the point, and correctly display title into the
info box when you mouse over. However, it can't find the object if you
click on (I would appreciate it open the post (post_status=future) as it
does for other post (post_status=publish)).

For a feature request, describe the feature.