You may wish to upgrade to v1.3.7.1 if this is a fairly new install ...
http://www.zen-cart.com/forum/showthread.php?t=69769

As to the Gift Certificates that are ordered and not released yet, those are in the table:
coupon_gv_queue

Once released there will be an entry in the table:
coupon_gv_customer

with the amount for the customers_id ...

When sent to someone, the email is then tracked in the table:
coupon_email_track
coupons

NOTE: when you claim the Gift Certificate with the redemption code, you will then see a balance in your Gift Certificate account in the table:
coupon_gv_customer

and it will show in the Catalog for your My Account and during checkout_payment you will see a place to redeem codes that have not yet been redeemed and a place to Apply some or all of the balance towards an order ...