You're forgiven!
And I suppose you mean specific gravity [salinity levels] not just gravity?
This sounds somewhat unlikely, however, you didn't say when you started cycling?? If you did your salt mixture and then took salinity readings right after the mix, then you probably just got an off reading due to the the salts not completely mixing yet. Hobbiest commonly "age" salt mixed water just so that we make sure that the salts are all dissolved very well before it ends up in the tank. "Aged" means the water is mixed and left with areation for at least a few days, if not more, before using it in our tanks. Some hobbists have a constant supply of "aging" water going at all times.
The other thing you need to look at is evaporation. Is your tank losing a lot of water due to evaporation? Any time that you add water due to evaporation loss, you need to add FRESH water, not salt water [water evaporates from the tank, not salt, thus when you add water due to evaparation, you need to replace the water, not the salt].
[This message has been edited by beth (edited 02-22-2000).]