Concrete Install Warning

I get the following warning when I try to install Concrete:
“You must chmod 755 concrete/libraries/3rdparty/ and disable PHP safe mode.”

Am I safe to assume that “PHP safe mode” is what Dreamhost calls “Extra Web Security” and “mod_security”? If so, is it safe to go without mod_security enabled? I’m mainly running a forum and will have a PayPal Donation button.

I read the Wiki Pages on this but I am unsure what .htaccess options I need to use. If anyone has experience with this I would appreciate your suggestions.

Edit: I disabled “secure hosting” and chmod 755 the file they requested but now I get this error:
“Cannot connect to database”. I copied and pasted the information from the Dreamhost installer robot properly.