oauth_problem="signature_invalid" response for compound query
I use java api for search, with Signpost library, everything set like in SignPostTest example class.
It all works fine when searching for single words, but if query is composed from two words (with + between them in http call), I get response
< <xmlns:yahoo=>'http://yahooapis.com/v1/base.rng' <xml:lang=>'en-US'> < >Please provide valid credentials. OAuth oauth_problem="signature_invalid", realm="yahooapis.com"</ ></ >