[imp] error renaming folders

[horde at rnet-tech.com]

Using HEAD version updated as of this morning.

I created a folder foo.  I went to rename the folder and after typing foobar in
the popup for the new name, I received this error (in black text at top portion
of screen):

Warning: Unknown modifier 'f' in /var/www/html/mail/horde/imp/lib/Folder.php on
line 513

Warning: in_array(): Wrong datatype for second argument in
/var/www/html/mail/horde/imp/lib/Folder.php on line 520

In addition, this error was on yellow background in the message area:

Renaming "foo" to "" failed. This is what the server said:

Please let me know how to correct this.

-eb

PS - I should mention that I am able to create and delete folders without a
problem.