When opening a Excel document in the IE a password is required
 

I have a Web server, on which is a directory-structure with Excel files. The
directories are protected with SSL and LDAP authentification in the root, it
take place a registration with the entrance into the directory - so far
everything is correct. When opening a Excel file with Excel2003SP1 1x the
SSL Certificate and 3x the LDAP Authentifizierung of the roots is required
again - I click 3x on Break during the registration, the Excel document
nevertheless opened. With Excel2003SP2 I must click only 1x on Break. Word
files and other documents are opened without any problem, the behavior arise
only with Excel files. On another computer I have to run Excel2000. There
it is like that with Excel2000 without updates, but bringing Excel2000 to
SR-1a the error is repaired. Here thus obviously an error arises, which was
already times eliminated in a previous version (see also ms knowledge base
article: 225234). Operating system is Windows XP/SP2, Browser IE6/SP2 -
everything up-to-date. What can I do - is there any solution or a Hotfix???