Sorry for not being able to reply earlier..
here,
direct link to the video explaining the problem.. [1mb]
As you can see if you need to select a long portion of a line, it might take quite a while.
I think it does not depend on syntax or line length (line length should be wider than the window, obviously

, thus, no word wrapping.).
In other text editors this works a lot faster. Besides, cursor distance usually allows to control the speed of selection.
Hippoedit v.1.46.723x64, vista x64.