If System Administrator creates a Survey_Question_vod record manually through the UI using an existing Question_vod record, the question is displayed.
When the user attempts to data load new records on Survey_Question_vod and links the Survey_vod and Question_vod records, the question remains blank.
This happens because it is not enough for the System Administrator to link the two parent records (Survey_vod, Question_vod). The user also needs to populate the Text_vod field with the same data present on the Text_vod field of the Question_vod parent record.
This does not happen when manually creating records because the Visualforce page code stamps the values of the Question_vod fields on the Survey_Question_vod records.
Whenever data loading Survey_Question_vod records, always be sure that the Text_vod, Answer_Choice_vod, and Language_vod fields have the same data as the parent Question_vod record.
CRM Help Documentation: Data Loading Surveys