Ipad 1 wont sync

[glanden]

I bought a program (with a couple add ons) through iTunes via my iPad (1st generation) several days ago. The program is fine and works well. Untill I synced it with my computer. Not only did it delete the drawing but now tells me I have to buy the product before I use the save function. In my bought products in itunnes it says i have bouhght it Now is this iPad, laptop of software issue or could it be. In my settings somewhere. Many thanks to all. I figure it's in the settings because it's more than 1 app