Update to 4.2.1: blank page

[ginkgo]

Hi,
when I tried to update 4.2.0d to 4.2.1-7017 I got a blank page and the update-process stopped.
What can I do, to get a correct update?
Thanx - ginkgo -

[ginkgo]

Now I tried the Patch SugarSuite-Upgrade-4.2.0-to-4.2.1a.zip.
Using again the UpgradeWizard in the Admin-section..
Result is the same.
Upgrading-process stopps at the following URL: .../index.php?module=Administration&view=default&actio n=UpgradeWizard_prepare
A complete blank page is shown an if I click on the URL again the Sugarsite opens with "File to install not specified."

Is there an alternative way to upgrade Sugar 4.2.0d with that patch?

Apache/1.3.27 (Unix)
PHP 4.4.2
MySQL - 4.0.24-max