Prestashop rewrite my htaccess file when adding new product

[ctini]

Hi, I had my old shop on www.domain.com/shop

I create the new version on root folder www.domain.com

So I put the htaccess file with all the 301 redirects.

I'm using pretty url with the new shop but I have a big problem; once I add a new product it rewrites the htaccess file so it changes from 79KB with all the 301 redirects to 7KB with no redirects...

How can I avoid prestashop rewrite my htaccess?

When can I delete the old shop on /shop folder. How many weeks or months I have to preserve the folder and the htaccess with 301 redirections?

 

Thanks in advance.

Edited December 12, 2012 by fjrm (see edit history)