tso.SetGeocode flagging UK geocode as invalid number

[Deleted user]

I am trying to constrain the area I search for tweets in the UK, but am receiving an error response from the TwitterSearchOrder.py module.

[code]C:\Users\cjadmin>C:\Users\cjadmin\Desktop\py\search.py
Traceback (most recent call last):
File "C:\Users\cjadmin\Desktop\py\search.py", line 26, in
tso.setGeocode(53.409144,-2.147483,10,'mi') # Set location constraints with
geocode
File "C:\Python27\lib\site-packages\twittersearch-0.78.3-py2.7.egg\TwitterSear
ch\TwitterSearchOrder.py", line 138, in setGeocode
raise TwitterSearchException(1005)
TwitterSearch.TwitterSearchException.TwitterSearchException: Error 1005: Invalid
unit.[/code]

I've tried escaping the minus for the geocode but that also fails.

Are UK codes unsupported?