Testing has shown problems with this combination. Here's why:

First, the Sonic Maximizer does not come with an RTAS (Pro Tools-compatible format).

Second, there are known problems when using the FXPansion VST to RTAS wrapper to change the VST format into a Pro Tools plugin.

You could make sure you have the latest version of both programs, and make sure to have the latest version of Pro Tools (and the latest CS updates from their website) to see if this helps.