After further investigation on basis of previous question url encode/decode is working properly. Issue is something with Apache server (might be) which serves file download request Specially if my file name ends with % sign, it fails. For e.g.

Original File name:

204153_20090605_Aluminiumacetotartraat_DCB_oordruppels_1,2%.pdf 



Url in browser after clicking on download link:

http://pdf/204153_20090605_Aluminiumacetotartraat_DCB_oordruppels_1%2C2%25.pdf

Bu kötü isteği ile 400 hata döndürür. Ben Kohana 3 çerçeve ile LAMBASI kullanıyorum.

Rehberlik edin.

Teşekkürler ilerlemedir.