Windows Live Mail problems

In Windows Live Mail I get the message "Folder could not be displayed" on Inbox, Sent items and all the Quick views folders. Possible causes are given as "Low disk space or Low memory". If I check Inbox properties it tells me that it contains 4944 messages, 4840 unread. However, if I look at Inbox and Sent items in the Windows Live Mail part of C:\ I find that they are empty.  All my Storage folders are intact and are accessible. Also if I search my user folder using .eml as search key all I find are the messages in Storage, which confirms that the properties report on Inbox is quite wrong. How can I recover the contents of Inbox and Sent and stop getting the "Folder could not be displayed" message?  One other anomaly is that when I start WLM I get the message "Recovering Windows Live Mail database" yet clearly it fails to do so.