Hi,
This is intentional. Due to automation-related issues we decided to implement the linking only as the feature of the plug-in editor allowing to setup two parameters at a time (one for left and one for right channel). The state of this button, however, is not saved in a session - it is only the underlying parameters which are saved, so whenever you load the session the plug-in sounds exactly the way it sounded on save.
_________________________
Hubert Pietrzykowski
DSP Engineer
PSPaudioware.com