i've install FC5 and also done some trick like edit the /etc/yum.repos.d/*.repo file
but when i want to add/remove software it stop and display this message

Component: Software Manager
Summary: TB43b34ebc GroupSelector.py:407opulateCategories:TypeError: iter should be a GtkTreeIter

Traceback (most recent call last):
File "/usr/sbin/pirut", line 363, in ?
main()
File "/usr/sbin/pirut", line 359, in main
pm.run()
File "/usr/sbin/pirut", line 288, in run
self._showBrowse()
File "/usr/sbin/pirut", line 225, in _showBrowse
grpsel.doRefresh()
File "/usr/lib/python2.4/site-packages/pirut/GroupSelector.py", line 410, in doRefresh
self.populateCategories()
File "/usr/lib/python2.4/site-packages/pirut/GroupSelector.py", line 407, in populateCategories
sel.select_iter(i)
TypeError: iter should be a GtkTreeIter

Local variables in innermost frame:
i: None
cats: []
self: <pirut.GroupSelector.GroupSelector instance at 0xb79b220c>
sel: <gtk.TreeSelection object (GtkTreeSelection) at 0xb4204aa4>

any idea how to solve this problem????

Don't use it, it's very buggy. Better use 'yum' from terminal or 'yumex/kyum' if you prefer GUI.
If your repos(fedora-extras) are properly setup, do(as root) a
Then you can easily add/remove software from your system.
And BTW, Welcome to LQ