WordPress 2.8 is out and I first tested it on my test site. The automatic upgrading was fine on my test site. I then tried to upgrade my production site. I got this message when I tried.
Fatal error: Allowed memory size of 33554432 bytes exhausted
It seemed like WordPress uses too much memory and it cannot do the automatic upgrade. I figured that it’s possible I have too many plugins running. I tried to de-activate some of non-essential plugins and I was able to upgrade it afterwards.
The other way to fix this problem is to edit the php.ini file in the wp-admin directory if you have one. If you don’t have a php.ini file, ask your web hosting company to create one for you. Edit it and find the line like this.
memory_limit = 64M ; Maximum amount of memory a script may consume (32MB)
The default is 32MB, I changed it to 64MB.