As a result of the 2009 Federal Budget announcements, many pensioners would have received various letters from Centrelink in relation to changes to their pension entitlement from 20 September 2009. These changes affect most types of pensions including Age Pension, Disability Pension, Wife Pension, Widow Pension, Service Pension and Carer Payment. 
Some of the changes are positive, like increasing the pension rates etc; however one major change that has affected numerous pensioners, even causing some of them to lose their pension, is the change to the definition of income under the income test. From 1/7/09 assessable income also includes reportable superannuation contributions (i.e. salary sacrifice contributions) and net losses from rental property or investment income. So if you salary sacrifice superannuation contributions or have a transition to retirement pension set up, you may be affected by this change.