The following bug has been logged online:
Bug reference: 4436
Logged by: Mathieu Fenniak
Email address: hjoiiv(at)mathieu(dot)fenniak(dot)net
PostgreSQL version: 8.3.3
Operating system: Linux x86-64
Description: (E'\\' LIKE E'\\') => f
Details:
I noticed that (SELECT E'\\' LIKE E'\\') returns false, where I would expect
it to return true. I asked on the #postgresql/freenode IRC channel, and
nobody had a good explanation for this return value, suggesting it may be a
minor bug.