Apple Mail Exporting mbox missing emails

[be...@meke.co.nz]

Hi Google Email Uploader Users,

I've recently switched my mail server to Google Apps. I want to consolidate all my mailboxes in Apple Mail so they all sit on the Google Server.

My process has been to select my previous email mailbox in Mail. Export to an .mbox file. And then use Google Email uploader to add to my Google mailbox. 

The trouble is, when I export my mailbox all emails before Aug 2011 do not get exported. At first I thought Mail mail and Google were counting the emails differently. But when I, for example export all sent mail from sent mailbox (1171 messages) and then import back into Mail, the import is only 817 messages (cut off date Aug 2011). Google Email Uploader also only reads 817 messages. Has anyone else had this problem? Any idea what is going on?

Thanks for your help,

Becky