Reverse for 'app_list' with arguments '()' and keyword arguments '{'app_label': ''}' not found.

[vijay shanker]

hi
i have this model called charity
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from django.db import models
from settings import DEFAULT_CHARITY_NAME as deafult_charity_name


class GetDefaultInstance(models.Manager):
    def get_default_instance(self):
        return super(Charity,self).get_query_set().filter(charity_name=default_charity_name)
  
   
class Charity(models.Model):
    class Meta:
        verbose_name_plural = 'Charities'
        app_label = 'charities'
    charity_name    = models.CharField(max_length=50)
    in_percentage   = models.IntegerField(help_text='default value is 0,\
                                          leave blank if you will enter fixed amount.', default=0, blank=True,null=True)
    fixed_amount    = models.IntegerField(help_text='default value is 0,\
                                          leave blank if you entered amount in percentage.',default=0, blank=True, null=True  )
   
    objects = models.Manager()
    default_instance = GetDefaultInstance()
   
    def __unicode__(self):
        return '%s'%self.charity_name

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in urls:
(r'^admin/charity_report/(?P<itemdetails_id>[-\w]+)/$', 'charities.admin_views.report'),
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and another model called ItemDetails which have forignkey relation with above model, with  default instance of charity attached to each Itemdetail object .
I wanted to add admin button alongside history button so user can see amount charged as charity and stuff like percentage deduction,amount deducted etc.

i managed to show the button but when clicked at it gives this trace:
http://pastebin.com/03wscYLX

the settings is at:
http://pastebin.com/7FYY189D

the other regular info are in:
http://pastebin.com/QmAdEeP9

its been 2-3 days trying to run it on apache server.. it works ok on local machine.

i override form_change template and provide the button, write urls for admin