My profiles dont reset back, however GpU tweak is bugged as hell. But if you can deal with
For example using OC Scanner the Mhz/V curve may get deleted if you hit Apply twice on this profile (will get linear as default Gaming Profile), also the display frequencies dont show the new max gpu boost after OC Scanner ran. Checking on GPU Z you can ensure check the true OC Freq applied.
I reinstalled last version 126.96.36.199 and my profile dissapeared, so i have to set up all again plus the OC Scan thing.
Settings of profiles looks to be saved on Registry, HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\ASUS\GPUTweakII havent checked if exporting them will serve as backup of your settings yet