Problem with index using regular expression

I my case I have create on index on the surname of users. 

CREATE INDEX  income_surname ON income(substring(income.name from E'\\w.*\\s(\\w.*)$|\\w+\\s(\\w.*)$'))

then used

SELECT Distinct On (nodes.id) nodes.ID from nodes inner join income on substring(nodes.name from E'\\w.*\\s(\\w.*)$|\\w+\\s(\\w.*)$') = substring(income.name from E'\\w.*\\s(\\w.*)$|\\w+\\s(\\w.*)$')

with psql the index works fine, but with psycopg I don't think it's used at all. The index substring has to be identical with the substring in the query. Are there some encoding issues with psycopg?

--
Håvard Wahl Kongsgård

http://havard.security-review.net/