Transferring WordPress Site: Issues with Core Files

Hello,

I’ve been struggling for a while now to transfer my WordPress blog from Hostway to GoDaddy. Here is what I’ve currently done:

1. Downloaded all core files and database from Hostway
2. Installed WordPress on GoDaddy, created database
3. Imported old database to new database, updated wp-config

I’ve uploaded the old wp-content file with no problems, and am currently previewing on GoDaddy and seeing my home page, posts, content, etc. exactly as it was before. However, whenever I try to upload the Hostway wp-admin or wp-includes files, I receive this error:

Warning: require(/home/content/85/11406485/html/wp-includes/revision.php) [function.require]: failed to open stream: No such file or directory in /home/content/85/11406485/html/wp-settings.php on line 120

Fatal error: require() [function.require]: Failed opening required '/home/content/85/11406485/html/wp-includes/revision.php' (include_path='.:/usr/local/php5_3/lib/php') in /home/content/85/11406485/html/wp-settings.php on line 120

The old site is running WordPress 3.4.1 (because Hostway does not provide automatic WordPress updates) while the new GoDaddy server is running WordPress 3.6. Could this be the source of the problem? How should I go about fixing it without risking breaking the live site? I don’t want to change my nameservers until everything is working properly. Please help!