My phone and text messages

My Blackberry pearl will recive a text message but when it does recive it, the phone deletes all the messages in the inbox and i dont get a chance to read them.

This issue is happening because the device memory is low. When the device's memory is low, the BlackBerry's Low Memory Manager kicks in and starts removing call logs and/or messages to clear space.

The link below shows some ways to free up memory on the BlackBerry device: