Links unstable

I have a recurring 404 error with broken links. When I first installed the Quickstart package, all links worked correctly. Then later, I got the 404 error whenever I clicked on a K2 item from the homepage newspro links, or from the category menu. It is possible that the problem started after I turned on SEF and URL rewriting in Joomla Global Config. It drove me nuts trying to find a solution, as I could not find the Gavick documentation page with a search on 404 or "url". But there is an article you can find titled "how to make links work again" https://www.gavick.com/documentation/questions/how-to-make-links-working/. I fixed the problem by creating a dummy menu that linked to my category. Problem solved, or so I thought, until 2 days later, there it was again!!

I don't know what triggered the problem to recur, because it was definitely fixed and all working OK for a couple of days. Possibly it recurred because I installed an additional Gavick module (for weather). But now that it had recurred, what was I to do, because I had already created the dummy menu item as per the documentation instructions the first time. I created a second one, but it made no diference. Then I read on another unanswered forum posting that someone had a 404 error problem whenever they had submenus in the main menu. So I got rid of the submenus, and the problem is fixed.

This is very scary. Even though the problem is fixed, I don't know what caused it the second time, and I don't understand what fixed it the second time. It's a beautiful template, I really like it, but I'm feeling that the template is unstable, and I have put DAYS of work in developing it. I hope someone can explain what is going on.

It just happened again!!! 404 error. All I did was change the title of the Joomla Main Menu item for my K2 category. This time I "fixed" it just by rebuilding the main menu. BIG BIG SIGH.

BTW, I'm running Joomla 2.5.6 PHP 5.3.13 GK Fashion Gavern v.3.3