unable to extract embedded font (Acrobat Reader problem after pdflatex)

Problem with teTeX beta (2.96.7.20040721) under Solaris 2.9.

After generating a pdf file with pdflatex, Acrobat Reader does not
extract all embedded fonts and complains "Unable to extract the
embedded font XXX". In the Reader output the missing characters are
shown as dots. For each file, only one (the latest?) of possibly
several embedded fonts can not be extracted by Acrobat Reader; that
is, in a pdf file with N different embedded fonts, N-1 are shown and
extracted correctly (if N=1, I get only dots).

Actually, the fonts seem to be available and embedded in the file:
viewing and printing the pdflatex generated file with xpdf or gv does
not produce the error message and output is ok. Also, generating a pdf
file from the same source along the "latex -> dvips -Ppdf -> ps2pdf"
output routine results in a pdf file which is accepted by the Acrobat
Reader.

The problem occurs with different versions of Acrobat Reader (5 and 6)
running on several platforms (Unix and Windows).

Any hints?

Thanks, Adrian.