After host migration -> Failed to open required PEAR_Error.php

[sergito]

After a host migration i get the following error into apache log:

[Thu Apr 14 09:43:56 2011] [error] [client *] PHP Warning: require_once(/....my....path/httpdocs/tienda/config/../classes/PEAR_Error.php) [function.require-once]: failed to open stream: No such file or directory in /....my....path/httpdocs/tienda/config/config.inc.php on line 18
[Thu Apr 14 09:43:56 2011] [error] [client *] PHP Fatal error: require_once() [function.require]: Failed opening required '/....my....path/httpdocs/tienda/config/../classes/PEAR_Error.php' (include_path='.:') in /....my....path/tienda/config/config.inc.php on line 18

facts:

- "....my....path" isn't real path, it's because privacy. "*" isn't my ip

- backend works

- I think $smarty is loaded ok because if i create a PEAR_Error.php file (which is a link to PEAR.php) and go to my shop, the navigator returns my the page but as downloadable file! This file is the correct html of my page, then y assume that smarty was executed

- i have pear installed in both machines, with the same features ("pear list" command) and config ("pear config-show" command)

- PEAR_Error.php doesn't exists as file, but PEAR_Error class is defined into PEAR.php, which is in classes/ folder

- i get a blank page when i open mi shop in IE, mozilla and chrome

- i've tried to add ps classes/ directory to include_path into php.ini with no success

- i've tried to add pear directory to include_path into php.ini with no success

any help would be grateful

regards