Some Eclipse Helios label decorations are not synchronized with Subclipse

I recently upgraded to Helios from Galileo, and to the Subclipse 1.6.x plug-in. Prior to the upgrade, all label decorations the Project Explorer reflected their state in SVN, e.g. if I changed a file in my workspace, the associated file decoration contained a white asterisk in a black background to indicate that the workspace and repository file differed.

After the upgrade, some files behave as before, but others are no longer synchronized in that manner and their is no indication as to whether they differ from their repository versions. For those files, their label decoration is (and remains) sort of a light gray rectangle with a backslash through it. Here is an image of it



and here is the label decoration that I expected, and which does appear for some files:



In some cases, I have two files in the same directory, where one synchronizes correctly while the other doesn't. Both files have the same permissions, and when I look at their Subversion properties, they show identical SVN Url, repository root, status, and properties status. If I change the file with the incorrect label decoration and do an SVN compare, it is correct and I can also check it in. Does anyone know how to fix this decoration problem? Thank you.