Hi,
I'm not exactly sure how to phrase this appropriately: Either "Debian GNU/Linux Etch corrupts Drupal 5.1", or "Drupal 5.1 is potentially incompatible with Etch", at least for non-English websites under some circumstances; I'm trying to find out, what these exact circumstances might be, and how to fix the failures caused by the upgrade.
_The Problem_
After upgrading Sarge to Etch, Debian includes PHP 5, MySQL 5, and Apache 2.2. With this upgrade, some 3rd party modules became disfunctional in Drupal 5.1, and all special characters, all German Umlaute, and all texts with non-English characters broke/got corrupted/were displayed wrongly. This applies _only_ to Drupal sites, other pages (static via Apache, or LAMP systems like MediaWiki or Gallery2) are not affected. Also, Drupal lost some configuration information due to the upgrade (e.g. site name, site description) which could be entered afterwards again. As it seems, Drupal is accepting Umlaute and special characters again (e.g. in the site name; currently I can't test it on nodes due to failures of 3rd party modules when previewing). Because of this behaviour, I suspect a problem with the transition/conversion from MySQL4 to MySQL5 which only affects _existing_ data (in my case, some 15.000 nodes).
Example 1 with some umlauts and typographic characters (after the corruption):