Sorting products

[Lars-]

Dear reader,

 

First of all, I don't know if this is the right category to post this in but I don't know where to put it elsewhere.

 

Okay. Situation: I am working on a webshop with about 150 products and approximatly 30 categories. Several products are listed in multiple categories. 

What I want is to sort the products. I actually know how to do that already. But what I noticed is that every product is resorted in the old way when I add a new product to that category.

 

So say that this is originally the situation:

Product 1: Position 1

Product 2: Position 2

 

I change it to:

Product 1: Position 2

Product 2: Position 1

 

But when I add a product, it get changed to:

Product 1: Position 1

Product 2: Position 2

Product 3: Position 3

 

Imagine this with about 50 products... Is there an other way to sort my products? Maybe with a module?

 

Thanks in advance.

 

Kind regards,

Lars Jansen