Author tag error in template

I have been having a weird error with this script for a while now.

This error happens once I move servers. On the old server, the theme worked perfectly, but once on the new one, it gives the following error.

The problem is the ‘author’ tag doesn’t seem to display – now this isn’t something that has always happened (which rules out that it’s incorrect), it’s happened on occasion when we change servers – but not on ALL sites which rules out a server problem I would assume. (Posted by: | 1 Comment / Leave a Comment) should read (Posted by: Name | 1 Comment / Leave a Comment)

See here – http://abbie-cornish.com/ & http://www.amyadamsfan.com/

I have looked into changing the author tag to the various ones (although it worked perfect before we moved servers) but nothing works at the moment.

And for instance, this same loop is on http://www.meganfoxdaily.com (same server too) and works perfect.

The same happened at http://www.michaelchall.org too but what helped there was to remove the drop down from the sidebar. But I would prefer not to go and remove it since I’m sure there’s another solution to this error.

For the record, I have tried re-upgrading several times. I am currently running on Version 2.6.2. I have the category images pluggin, wp page navi & wp grins – but all are on the current versions and I have tried disabling / re-enabling them multiple times but still no fix. Again, all worked perfectly before

Please assist or point in me in the right general direction, thanks.