In "imagegallib.php" the $archive->extractByIndex
around line 410 fails.
This is because $tmpDir is windows style "C:\TEMP"
(C-colon-backslash-TEMP) for instance, and PclZip adds
"./" (dot-slash) in front of the path. That results in
an output path that looks like this "./C:\temp"
This makes extractByIndex fail, thus not unpacking any
files, and making the upload fail. My own temporary
solution is to remove $tempDir and manually insert a
relative path, but that is not a good solution IMO.