syntax higlighting always fails

[g-i-o-r-g-i-o]

I've been using this addon for months, and I have never had a consistent experience.

When editing long markdown files, the higlighting fails continuously. I have to do :w and :e very often, only to lose all the syntax coloring minutes later...

The markdown file has a lot of python blocks, and indented blocks.

I've already tried to set
set synmaxcol=1000

Please suggest me how to fix this, and if possible give me a vimrc to test your configuration.