[imp] Javascript Trouble for IMP4 with Internet Explorer 5.5

[eugenio.vota@arpnet.it]

Hi all,

I'm installed IMP 4.0.3 over Horde 3.0.4 , Kronolith 2.0.3 , Turba 2.0.2
and all work very well with IE 6 , Mozilla 1.7.x , Firefox 1.x  ...

but with Internet Explorer 5.5 on Windows 2000 SP 4 
when I click reply link (also for  reply-all , forward , new-mail)
 in the message.php page ( the "Compose messages in a separate window? " 
option is TRUE)
the new compose windows doesn't appear
and IE report this error

        Error
        A Runtime Error has occurred.
        Do you wish to Debug?

        Line: 0
        Error: Object expected


However if  I change someone of my preferences, such as color scheme for 
example, the trouble doesn't appear until the next login !

I looked for anywhere, but I've found only  this  report by MS
    http://support.microsoft.com/?scid=kb%3Ben-us%3B269446&x=18&y=7

Someone have any suggestion about?
Why when I change some options the trouble doesn't appear?

Thanks all and congratulations for your very cool jobs.