MaxRedirects/Recursion error using PHPRoad Db_ActiveRecord

I'm making additions to a Lemonstand v1 site, but only realised after a few days that the same error was occurring on the pages that I was amending; they seemed to take a while to load (on localhost) and then would error out with a 'Connection Reset' message. I'm pretty sure this kind of error is the result of a redirect loop or similar, and the local Apache error logs seem to bear this out:

[Sat May 24 14:35:23.487444 2014] [rewrite:warn] [pid 3492:tid 1744] AH00664: RewriteOptions: MaxRedirects option has been removed in favor of the global LimitInternalRecursion directive and will be ignored.

...repeated about 30 times. In both cases I was making a database call via the Db_ActiveRecord method upon which much of Lemonstand is based. Both calls were completely different, but essentially did the same thing: made a call to the database to find all instances of a record by ID or similar. For example:

$orders = Shop_Order::create()->where('customer_id=?', $this->customer->id)->order('order_datetime desc')->find_all();

Regardless of what I do with the resulting $orders (including doing nothing with it, just declaring it), this line alone causes the error. If I comment it out, the connection reset doesn't happen. This happens elsewhere with a completely unrelated module call which similarly uses Db_ActiveRecord:

$faqCategory = AhoyFaq_Category::create()->find_by_id($product->productFaqs_faq);

Again, if I just remove that call, the pages load as normal, without recursion issues.

If you're interested in taking a look at the .htaccess file, I've put it here - but it's a completely default .htaccess for Lemonstand, so I'm not sure that's where the problem lies. I've also put the full access log (at least, the list of errors following a page refresh) here.

I've got NO idea why a DB call would result in this kind of recursion, so if anybody has any clue, that would be great. Thanks guys.