How to include graphics from parent directory using \graphicspath?

To include graphics from parent directory I am using

\usepackage{graphicx}
\graphicspath{{../pop/}{../graph/}}

This works fine for MiKTeX but seems to fail for TeX live installed on the same computer (compiler did not find graphics files).

What I'm doing wrong? The directories PoP and Graph are located on the same level as the working directory with the source LaTeX file.

Update: Directory structure (for test purposes I put same graphics files in PoP and Graph subdirecrtories)

ECRH
|- OS2012
|  |- ECRH(proc).tex
|- PoP
|  |- ECRH-Fig1.pdf
|  |- ECRH-Fig2.pdf
|  |- ...
|- Graph
|- ECRH-Fig1.pdf
|- ECRH-Fig2.pdf
|- ...
-
Are the directory names correctly capitalized? –  egreg Jul 18 '12 at 8:07
@egreg: I tried \graphicspath{{../PoP/}{../Graph/}{../eps/}} with the same results. –  Igor Kotelnikov Jul 18 '12 at 9:38
Can you please add a scheme of what you have? –  egreg Jul 18 '12 at 9:44
@egreg: please see update. –  Igor Kotelnikov Jul 18 '12 at 13:12
On my system it works (<use ../PoP/pop.pdf> is one of the messages). But it's not Windows. –  egreg Jul 18 '12 at 13:22