Does iPython cache older versions of libraries?

ipython caches libraries

# using ipython 1.2.1 on Ubuntu 14.04

# I have a cloudant-python library installed in a virtualenv
# there was a bug, which I fixed, and ipython-notebook kept
# showing the old behaviour. ipython in the console also shows
# the old behaviour:

$ ipython
WARNING: Attempting to work in a virtualenv. If you encounter problems, please install IPython inside the virtualenv.
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
Type "copyright", "credits" or "license" for more information.

IPython 1.2.1 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: USERNAME, PASSWORD = 'foo', 'bar'

In [2]: DBNAME, DOCNAME = 'thermostat', 'stratus-device-0000000'

In [3]: 

In [3]: from cloudant import Account, Database, Document

In [4]: account = Account("http://localhost:5984/")

In [5]: response = account.login(USERNAME, PASSWORD)

In [6]: account.all_dbs().json()
Out[6]: 
{u'couchdb': u'Welcome',
 u'vendor': {u'name': u'The Apache Software Foundation'},
 u'version': u'46cb6a4'}

# the above is not the expected outcome, and this is a bug
# that I had already fixed...

In [7]: 
Do you really want to exit ([y]/n)? 

# but the python cli does find the current library installed
# and shows the good behaviour

$ python
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> account.all_dbs().json()
KeyboardInterrupt
>>> SERNAME, PASSWORD = 'candeira', 'candeira'
>>> DBNAME, DOCNAME = 'thermostat', 'device-0000000'
>>> 
>>> from cloudant import Account, Database, Document
>>> account = Account("http://localhost:5984/")
>>> response = account.login(USERNAME, PASSWORD)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'USERNAME' is not defined
>>> USERNAME, PASSWORD = 'foo', 'bar'
>>> DBNAME, DOCNAME = 'thermostat', 'device-0000000'
>>> 
>>> from cloudant import Account, Database, Document
>>> account = Account("http://localhost:5984/")
>>> response = account.login(USERNAME, PASSWORD)
>>> account.all_dbs().json()
[u'_replicator', u'_users', u'hello', u'test']
>>> 
KeyboardInterrupt
>>> 

# and no, the cloudant library is not installed outside
# the virtualenv...

$ deactivate
kandinski@desire:~/data/work/hack/couchdb-fauxton$ python
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import cloudant
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named cloudant