When project number 2 tries to log an exception, i get this in sentry output:

Traceback (most recent call last):
File "/srv/beta.busyflow.com/code/eggs/sentry-3.7.2-py2.6.egg/sentry/manager.py", line 478, in from_kwargs
group, is_new, is_sample = self._create_group(event, **group_kwargs)
File "/srv/beta.busyflow.com/code/eggs/sentry-3.7.2-py2.6.egg/sentry/manager.py", line 621, in _create_group
value=value,
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/manager.py", line 134, in get_or_create
return self.get_query_set().get_or_create(**kwargs)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/query.py", line 449, in get_or_create
obj.save(force_insert=True, using=self.db)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/base.py", line 463, in save
self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/base.py", line 551, in save_base
result = manager._insert([self], fields=fields, return_id=update_pk, using=using, raw=raw)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/manager.py", line 203, in _insert
return insert_query(self.model, objs, fields, **kwargs)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/query.py", line 1576, in insert_query
return query.get_compiler(using=using).execute_sql(return_id)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/models/sql/compiler.py", line 910, in execute_sql
cursor.execute(sql, params)
File "/srv/beta.busyflow.com/code/eggs/Django-1.4-py2.6.egg/django/db/backends/sqlite3/base.py", line 337, in execute
return Database.Cursor.execute(self, query, params)
IntegrityError: columns key, value are not unique

Worked around by running this query in my sqlite3 console:

drop index sentry_filtervalue_key__value;

Also, if the same exception is reported in 2 different projects - it gets added to the project that first encountered it.