HPGAPTOL doesn’t “just work”
The new variable HPGAPTOL was supposed to allow the user to specify the maximum size of gaps that can be ignored when creating a hatch. It wowed the crowd in the 2005 demonstration that I went to. In practice, the variable setting rarely works.
Workarounds: Some users have reported that selecting objects (rather than internal points) yields better results. Others have stated that no segment of the boundary can be shorter than the value of HPGAPTOL. Even when using these techniques, many users are unable to produce consistent results.
First Appeared: AutoCAD 2005
Status as of 2008: Still reproducible
Status as of 2009: Still reproducible
Status as of 2010: Seems to have gotten better.