problem logging into one single encrypted website after upload to 9.04

[g.]

(posting from the software forum to this one, maybe this is more appropriate)

Hi,

I'm experiencing a very strange problem. since my upload to kubuntu 9.04 I can not logging into one single password protected website.

All the other encrypted sites work fine (from the bank to the credit card etc) except this one that is, obviously, one of the most important one.

Both under Firefox (3.0.10) and Konqueror (4.2.2) the site replies telling me that
"The password you entered didn't match for the username" which is obviously untrue.

The site is

http://ieeexplore.ieee.org

and, yes, logging in from Firefox under Windows it works fine...

Thanks in advance for any suggestion.
Best
g.