During the next few weeks, eBay Canada will be making a change to the Store Inventory listing durations.  Right now you can choose to have your Store Inventory listings run for several different lengths of time (ranging from 30 days to 90 days), or until you choose to cancel them. Ebay is removing the 90 day duration.

Any Store Inventory listings that you’re already running with this duration will not be affected. You will just not be able to list new items, or re-list closed items, with the 90 day duration once the change is made.

Here is the original announcement:  http://www2.ebay.com/aw/ca/200601131418212.html