Note: This is for customers using the SanDisk Gruvi card only.
Some programs will intercept the notification when a card is inserted into the device. Documents To Go does this for example.
If you insert the card and nothing happens, then please refer to this Knowledge Base article, http://www.normsoft.com/kb/idx/23/126/article/ , on how to manually install Pocket Tunes for playing back Gruvi tracks.