Thanks a lot RoiPatrick ! I will try to follow your advices and I will report back the result. Note: I had Java 1.6.0.7 and already made those uninstall and install actions what you suggested but with no detailed cleaning, so..let's go do it all over again

( As for new version : I use Update Checker and the new version offered is 1.6.0.12 , the error message refers to a missing installation file jre1.6.0_11-c.msi . After the message I have no other idea but choose the button 'cancel' installation. Then appears the message box: Error 1714, unable to remove the older version. Hey, it seems to be quite logical : I never had ver.1.6.0.11 installed so it can not be removed, right? This is why I went to oldapps.com to find it, but there was only ver.1.6.0.7 .
Thanks again, talk to you soon, have a nice day
Allisa