[Abagail]

It is very much likely to be a permission issue if the GTA settings don't save as it isn't controlled by SA:MP(though SA:MP offers some different screen resolutions I believe). Have you tried setting gta_sa.exe to run as administrator(through file properties)? All the samp.exe file really does is inject into gta_sa.exe, and the rest is typically controlled by THIS file and not the SA:MP application. What operating system are you currently running on?