While playing around with Eclipse (Helios) SVN plug-ins, I just run into the following ‘strange’ error: “Cannot map the project with svn provider”.
I figured out that when installing and removing plug-ins, especially when doing it manually (deleting stuff from the ‘plugins’ & ‘features’ directory), the configuration files located in the workspace directory have to be cleaned-up as well. The plug-ins re-write them in a clean version later. Doing this got rid of the error message and SVN worked fine.
(NB. possibly multiple directories)