Trying to import a PST and I keep getting this error:

12-05-2008 16:19:22 [7576]: ZCSPSTImportWizard-5.0.5_GA_2199 Version 5.0
12-05-2008 16:19:22 [7576]: Creating / starting worker thread
12-05-2008 16:19:22 [7576]: Dispatching work to worker thread
12-05-2008 16:19:22 [464]: Worker thread started
12-05-2008 16:19:29 [464]: Unable to open default msg store: -2147221219 at .\mapi\MapiObjects.cpp(623)
12-05-2008 16:19:29 [464]: Worker thread exiting


Any pointers?