I have been testing imports of old material using a wordpress xml file. Only one or two posts at a time for the test, Just as I nearly got there with the formats the wordpress import page (where you normally select the file) has now frozen with the message “error while performing blog import” and has been like that since last night (about 9 hours).
It says contact support – but of course support aren;t there.
OK, I’ve tagged this thread so that staff will hopefully see it and reply shortly to your problem and get it fixed for you. They are not back in the office till the 19th, but they are monitoring the forums.