Apple has acknowledged that its latest OSX update, version 10.5.6 may cause some users issues when it comes to using its own email application Mail.

In a support bulletin on the Apple website, the company states:

"After updating to Mac OS X 10.5.6, Mail may unexpectedly quit. This can be caused by having outdated third-party Mail plugins installed, or by using a copy of Mail that wasn't updated properly (you may need to install Mail Update 1.0)".

Apple users have hit forums and message boards across the web complaining about the problems the new update has caused.

Apple recommends running the software update again to see if their copy of Mail is up to date before taking further action.

"If the issue still persists, update any installed third-party Mail plugins to the latest version(s). For example, two third-party plugins whose earlier versions could cause this issue are OMIC and GPGMail", says Apple.

The bad news, warns Apple, is that if the suggested fixes don't work it recommends temporarily reverting back to version 10.5 and then running the update to 10.5.6 again.