[imp] Imap client socket erros - resource expected

[Luis Felipe Marzagao]

Hello:

I'm geting endless erros like these in the logs:

May 28 00:00:09 mserver HORDE: [imp] PHP ERROR: feof() expects parameter 
1 to be resource, null given [pid 3227 on line 4190 of 
"/usr/share/php/Horde/Imap/Client/Socket.php"]

May 28 00:00:09 mserver HORDE: [imp] PHP ERROR: fgets() expects 
parameter 1 to be resource, null given [pid 3227 on line 4203 of 
"/usr/share/php/Horde/Imap/Client/Socket.php"]

Does anyone have a hint on what may be causing it? Would it be imapproxy 
related? How can i further debug it?

Thanks in advance.
Luis Felipe