500 Internal Server Error — .htaccess (Siteground)

Hello everybody, I just wanted to report an issue I've found trying to run Grawlix on Siteground.
Setup went fine — I followed the instructions and managed to access the Grawlix Panel (interface looks really sleek btw!) but the health check warned me that it couldn't find the .htaccess file.
So I changed its name from htaccess.txt to .htaccess, as per instructed, but doing so inevitably causes a 500 Internal Server Error.
Commenting out either "Options -Multiviews" or "php_flag register_globals" doesn't solve the problem.
Then I tried to do the same with lines 3 and 4, and the site actually comes back; the health check now telling me everything's ok. I don't have to comment out Options-Multiviews also.
Just for more clarity, this is what it all looks like now:

# Set these to “1” to display PHP debugging info on most web hosts.
# php_value display_errors 0
# php_value display_startup_errors 0

# Got a code-500 error? Comment this one out first and try again.
Options -Multiviews

# Still got code-500 trouble? Then try commenting this one out.
# php_flag register_globals off

I don't know much about coding though, is this a viable solution? Or is it gonna cause trouble later on?