Comment 3 for bug 1205397

Workaround:
1) boot via "Try Lubuntu" not "Install Lubuntu"
2) open terminal
3) enter "swapoff --all" press enter
4) start installation

This workaround works only if the unsafe swap error has not been raised since the last reboot.
If that has been the case even with swapoff --all the installer will fail, to circumvent reboot.