You should create an after-submit process of type 'Clear Cache for Items (ITEM, ITEM, ITEM)', and specify your checkbox in it.
Checking the checkbox, making a selection and then submitting the page implies that you want to process this selection made but do not want to have the checkbox retain its saved session state (ie having been checked). By clearing its cache you will reset it to the default state.
If 3.2 has no such process, you could use a plsql process or computation to set the value of the checkbox to 0 or null (whichever value is the default value).

Apex 3.2 Button to call javascript
It is sometimes said that the universe is homogeneous and isotropic. What is meant by each of these descriptions? Are they mutually exclusive, or does one require the other? And what implications rise because of this?
