Subject says it all.
MediaWiki 1.8.2 (latest release) worked fine under XAMPP 1.5.4a
I installed a second machine with XAMPP 1.5.5, and it is now broken and not rendering some pages correctly, even though the MySQL database has the same tables (doing a 1:1 transfer of data using a dump export/import process).
Reverting back to XAMPP 1.5.4a by uninstalling 1.5.5 and installing 1.5.4a and all is well again.
Something is broken, but I am not sure what. My guess is that it's probably PHP related.
Any ideas ?