Can't login to webmail on IE

[hostshelter]

Hi Everybody,
I have a client is unable to login to horde web mail on internet explorer. he doesn't get any php error just "error on page" on the status bar of the browser.

I upgraded yesterday from plesk 7.5.2 to 7.5.3 on linux 3ES. Does anyone has a situation like?.

I appreciate any comment about it.

Thanks

Miguel