Fatal error while importing one WP to another domain & server

Hi WP community, yesterday I was trying to import an existing WP blog from one domain and server to another domain and server. However, the import failed due to the following fatal error:

Fatal error: Uncaught exception ‘Exception’ with message ‘Serialization of ‘SimpleXMLElement’ is not allowed’ in /file directory…./wp-includes/functions.php:336

Stack trace: #0 /file directory…./wp-includes/functions.php(336): serialize(Object(SimpleXMLElement))

#1 /file directory…./wp-includes/meta.php(60): maybe_serialize(Object(SimpleXMLElement))

#2 /file directory…./wp-includes/post.php(1731): add_metadata(‘post’, 4264, ‘posterous_446f7…’, Object(SimpleXMLElement), false)

#3 /file directory…./wp-content/plugins/wordpress-importer/wordpress-importer.php(741): add_post_meta(4264, ‘posterous_446f7…’, Object(SimpleXMLElement))

#4 /file directory…./wp-content/plugins/wordpress-importer/wordpress-importer.php(116): WP_Import->process_posts()

#5 /file directory…./wp-content/plugins/wordpress-importer/wordpress-importer.php(92): WP_Import->import(‘/home1/leizmonk…’)

#6 [internal function]: WP_Imp in /file directory…./wp-includes/functions.php on line 336

Any ideas as to what might be causing this?

The originating WP is hosted on 1and1.com running PHP version 5.2 and SQL version 5.
The intended import server is running on Hostgator with PHP version 5.2.17 and SQL version 5.5.33-31.1.

Could the difference between the versions be the cause? If so, how can I fix it? At this point my backup plan is to import the DB from the originating site to the new site, and upload all the files from the original site to the new one… would obviously prefer not to have to do that if I can get the import to work.

Thanks in advance for your help.