Fix: Parameter 1 to theme_imagefield_widget() expected to be a reference ....

warning:

Parameter 1 to theme_imagefield_widget() expected to be a reference, value given in your URL\includes\theme.inc on line 617.

Fix:
search for 'imagefield_widget.inc' in your modules directory:
now within this file search for

'function theme_imagefield_widget(&$element)'

update it with:

'function theme_imagefield_widget($element)'

Reason:
compatibility problem with PHP 5.3

FIX - Deprecated: Function ereg() is deprecated

Deprecated: Function ereg() is deprecated in drupal-6.14\includes\file.inc on line 902

FIX:
Find the below line:

elseif ($depth >= $min_depth && ereg($mask, $file)) {

Update it to:

elseif ($depth >= $min_depth && mb_ereg($mask, $file)) {