I think I am not the only poor soul to meet this problem. OK, if you have seen

There is a problem with this windows Installer package,
A program run as part of the setup did not finish as
expected. Contact your support personnel or package
vendor.

then, you know what I am talking about. After downloading the Apple Itune package, I just can not install it. So stupid. Quick way to fix:

Control Panel -> Uninstall your QuickTime.

Yes, unintall your QuickTime not the Itune. Then you give it shot, you now should be able to install the new version of Itune.

if you get an error like this when you turn on the similar post plugin

Error activating similar-posts/similar-posts.php for blog id=xxxxxx:
Warning: array_flip() [function.array-flip]: The argument should be an array in /home/your-domain/public_html/my/wp-content/plugins/similar-posts/similar-posts.php on line 572

then please check your line 572.

The solution is easy:

$overusedwords = array_flip((array)$overusedwords);

just put (array) over there.

Two steps you have to follow to fix the problem

1. memory_limit = 32M ; Maximum amount of memory a script may consume (32MB)(if you are 32M, then double it to 64M)

2. in wp-settings.php at line 13, increase from 32M to 64M (if you are 32M, then double it to 64M)

The symptoms you are going to meet for memory exhaust will be like accessing blank page of wp-admin, you can not visit your theme design page(too many theme loaded), or you can not access post page. They more all link to memory exhaust problem. The reason you know that you may have too many plugins, themes or some bad coding plugin/theme.

Some plugin may have the conflicts of the current 2.6 version wordpress so does wpmu.

Here is one type of error

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘media_admin_css’ was given in ~/wp-includes/plugin.php on line 311

The “solution” is simple. Edit wp-includes/media.php

put this new function at the end of the file

function media_admin_css() {
wp_admin_css(’css/media’);
} 

Just put right before the last