User mad eposts/tpics, but its not shown on "Username's Activity" tab

[postcd]

Hello, when i click some username in vbulletin im at url like:

http://myforum.com/members/username-6/

im on "Username's Activity" tab, but i dont see any posts/topics even this user made topics and posts. Another users with recent activity i see their postings, but some users not.

It appears that vbulleting showing only activity in last x days? where can i increase this period, is it good idea to do it?

thx