TJ operator does NOT display all glyph

Hi everyone,

I have a strange behaviour when generating a PDF document by using the TJ operator:

I am using the TJ to justify multibyte glyphs.

For example this:

BT 297.640 640.940 Td /F1 10.0 Tf () Tj /F2 10.0 Tf [(Lorum) 459 (Ipsum) 459 (dolar,) 459 (etc) 459 (June) 459 (4th,)] TJ /F1 10.0 Tf ET

is rendered correctly justified in Chrome viewer and Foxit Reader.

But the same PDF document in Acrobat Reader and Adobe Acrobat 9.0 is only showing "Lorum dolar, June".

So "Ispum", "etc" and "4th" are missing.

Acrobat Preflight reports the following error:

Any ideas?

Thank you in advance