w3 total cache and flush

I use w3 total cache, because page is too slow without it. So when I turn gzip on sometimes I got invalid characters on page. At the FAQ of total cache :

" I see garbage characters instead of the normal web site, what's going on here?

If a theme or it's files use the call php_flush() or function flush() that will interfere with the plugins normal operation; making the plugin send cached files before essential operations have finished. The flush() call is no longer necessary and should be removed."

So how I turn off flush?

Now I'm forced to turn gzip off, but I realy need that on

Hello,
There's no flush() or php_flush(), but in the widgets included in the theme there's ob_get_flush() function and generally these widgets are already cached, please try to set the cache time to "0" in widgets cache settings.