I'm guessing you're running it on Ubuntu or Debian, or a derivative. The packaged .debs are sorely outdated and buggy. If you're on Ubuntu or similar, you can add a ppa[1] for the daily builds which in my experience are much more stable than the old .deb releases. If you're on another distro or OS there may be a current release for you here[2]. Or, if you'd just prefer building from source, you can get it from their github repo[3].

[1] https://launchpad.net/~pinta-maintainers/+archive/ubuntu/pin...

[2] https://www.pinta-project.com/releases/

[3] https://github.com/PintaProject