product navigation error : next and previous product = the same product !

[isengart]

I updated yesterday to the latest version and i noticed that in one of my product The previous / next product its the same. I searched to my db and virtuemart products to see if i have a duplicated product but there wasnt any.
To be more specific i would try to explain it with the below Example

Top 4 products
Product1 - Product2 - Product3 - Product4 - Product5

Product1_NEXT-> product2

Product2_Previous->product1
Product2_Next->product1

Product3_Previous->Product1
Product3_Next->product4

Product4_previous->product3
Product4_previous->product5

Any ideas why this would happen ?

[Milbo]

depends on the ordering. Same product should be actually prevented.