Copying WordPress instance from Linux to Vista

I did the following to copy my production instance to a dev instance on a Vista box.

1) export database to localhost.sql
2) change all references to old url to new url in localhost.sql
3) import database onto new server
4) tarred up the WordPress files on Linux server
5) unpacked files onto the windows box.

All looks good except I get the following message on the top of each page:

Warning: array_keys() [function.array-keys]: The first argument should be an array in C:\development\wamp\www\jupiterthree\wp-includes\widgets.php on line 1843

I googled this and saw that this might be a common problem, just couldn’t find anything on a solution.

Any help is appreciated!

Ed