Upgrade >>> Database connection failed. Help!

[vaughnt]

It's been Upgrade-a-palooza around here. I have roughly 70 CMSMS installations, some dating back to 0.12.2, and I've been upgrading them all up to current 1.0.8  installs. I'm on a Linux based system, so I wrote a script or three to help me do the upgrades, and that has gone swimmingly. Run my upgrade script, visit /install/upgrade.php , do the db upgrade, and then run my cleanup script. Sweet. Oldest versions require a bit of additional work, logging in to the admin and updating settings, but it's all good.

Out of all my upgrades, only three installs have given me a problem I can't solve. It's the same problem on all three. When I try to run /install/upgrade.php, it says "database connection failed", and it wipes config.php clean. I can tell when it's going to do this because it detects the db schema as version 1. Looking at the install script, upgrade.php sets schema value to 1, then updates after accessing the db (I think). I originally thought that the wrong db schema was causing the problem, but now I think it's the failure to connect to the db.

All the installs are working installs in live sites, which means the db info in config.php should be correct. I tested the info in config.php by connecting to the db manually, using:
mysql -u username databasename -p
and supplying password. I am able to log in this way just fine.
Where else should I be looking to correct the database failed error when upgrading? Can anyone recommend a test procedure to find the cause?

Two of the installs that are failing to upgrade are 0.12.2, and one is 1.0.2.
MySQL is version 4.1.22
Server is Apache 1.3.37

Help?

[vaughnt]

Bump... Anyone have any ideas?