Problem when the phone is awakening



I faced with the problem: when I ran my application and waited for some time - the phone began sleeping. After that I awaked it and something changed. Fisrt of all I noticed that smooth filters for textures had become different, then I noticed that something wrong with the scaling. For example, I had two sprites which should be merged in the final picture(I mean on the screen). So for different resolutions I had to scale one of the sprites to not to allow any gaps between them. All worked fine until I awoke the phone. When I did it the gaps appears again.
Did anyone know how to solve the problem ?

Thanks in advance.