Data Merge not bringing in data from all the fields consistently

Hi! I created a template for a Data Merge in Indesign, and am using an Excel .csv file for data source (including image paths). Everything seems to be going swimmingly, BUT THEN... I see that some fields aren't being brought in on just a few of the entries. So I have it set up for name, title, company, and email address, but on some of them the title is missing or the email is missing, even though those entries DO have titles or emails in the correct fields. Data merge is also creating 2 completely empty instances on the second-to-last page, then the last entry shows up all by its lonesome on the last page. Any ideas what might be going on? Thanks.