Fatal error: Cannot access empty property in /hsphere/local/home/...../includes/common.inc on line 3520

Hi,

Hope someone could help. I've been searching if someone has solved a similar problem but I cant find solutions.

I am having this error after trying to create any new node in a new installation of Drupal 6.19, PHP 5.2.12 and MySQL 5.0.41, jQuery UI 1.6 and 141 active modules. After filling in the details of any content node from any of my categories and pressing on "Save" then I receive the following error in a white page and have to go back to the node's filling form. However, I noticed that the nodes are inserted in the database.

Fatal error: Cannot access empty property in /hsphere/local/home/...../includes/common.inc on line 3520

Looking at the common.inc file I see that the error originates here:

3503 // Build the SQL.
3504 $query = '';
3505 if (!count($update)) {
3506 $query = "INSERT INTO {". $table ."} (". implode(', ', $fields) .') VALUES ('. implode(', ', $placeholders) .')';
3507 $return = SAVED_NEW;
3508 }
3509 else {
3510 $query = '';
3511 foreach ($fields as $id => $field) {
3512 if ($query) {
3513 $query .= ', ';
3514 }
3515 $query .= $field .' = '. $placeholders[$id];
3516 }
3517
3518 foreach ($update as $key){
3519 $conditions[] = "$key = ". db_type_placeholder($schema['fields'][$key]['type']);
3520 $values[] = $object->$key;
3521 }
3522
3523 $query = "UPDATE {". $table ."} SET $query WHERE ". implode(' AND ', $conditions);
3524 $return = SAVED_UPDATED;
3525 }

I was wondering if there any way of identifying whether one of my active module might be causing the error.

Any help on how to fix this issue will be very much appreciated.

Thanks