A Notice error is thrown if replying to an activity in Activity Administration

[imath]

In the administration of the activity, if i ajax reply to an activity, then it throws a notice error about the Undefined index: hook_suffix in /wp-admin/includes/screen.php at line 402. The problem seems to be that the screen argument is not defined in the construct method of BP_Activity_List_Table.

So i suggest the diff attached to this ticket which also strips the call to get_current_screen() in the prepare_items() function and replaces $screen->id by $this->screen->id in the $per_page var.

[boonebgorges]

Looks good at a glance, but I'd like to wait until 1.9, as the current notice isn't hurting anything and I haven't dug deep enough into the root issues.

[boonebgorges]

In 7473:

Avoid PHP notice when leaving activity comments in Activity Admin.

Fixes #5068

Props imath