Steps to reproduce:
1. Open "Resize image" dialog
2. Set any value for parameters
3. Click save preset and enter a name
4. The preset is either saved with the wrong values (none?) or restored with the wrong values.
Not sure if this is Linux specific. Can anyone reproduce and confirm?
Interestingly, the "Last used" preset also doesn't load the actual last used values, and instead gives bad values.
Settings values to be saved as preset

Entering a name for our preset as an example:

The preset is not saving the right values:

Note: I could not find out where those values are stored on disk, not even through strace.