The following bug has been logged on the website:
Bug reference: 6617
Logged by: Dra=C5=BEen Odoba=C5=A1i=C4=87
Email address: dodobas@geoinfo.geof.hr
PostgreSQL version: 9.1.3
Operating system: Linux 3.3.3
Description:=20=20=20=20=20=20=20=20
When tried setting FETCH FIRST parameter dynamically in RETURN QUERY EXECUTE
some_query USING param1 it resulted with a syntax error on FETCH FIRST
parameter.
Apparently, it only accepts constants so it works with ($1)=20
Bug example: https://pgsql.privatepaste.com/1e3ef786a5