Hi Carlos,
currently I do not have Acroread installed. I try later if that changes anything. There is one other interesting thing: after "printing" the initial PDF -- the one with the wrong suffix -- the combo box in the new tab which lists the four possible file types/extensions (PDF, HTML, Excel, CSV) works perferctly.
Steps to reproduce:
* Execute process "Test jasper"
* iDempiere prompts to save "Test jasper - attachment-PruebaOSGi.jasper"
* Select "HTML" in combo box (HTML is shown)
* Select "PDF" in combo box
* iDempiere prompts to save "reportFrame.pdf"
This suggests that there may be two different procedures which construct the filename which is shown for download. The second method seems to be more robust with regard to the filename extension.
Best regards
Michael