Strange behavior with attachments

[skb]

Our forum has been experiencing something strange happening with the Attachments ever since 2.1 was introduced. Briefly, this is what happens (only some times)

We have a topic for Daily Quotes where the norm is to attach an image (usually jpg or png) and this works fine. The issue is that a thumbnail of the same image also gets attached to another post in another topic without cause. The frequency of this happening is like 1 in 20. This is happening only with my account as an Admin and not with the others. 

The only Mods we use are TP, Welcome Topic and a Custom Mod which has nothing to do with Attachments.

[Aleksi "Lex" Kilpinen]

What version of 2.1 exactly, and is this still happening?
There were some odd issues with attachments early in 2.1 I think, but there shouldn't be any like this anymore.

[skb]

2.1.4
It hasn't happened for some days now, but I haven't updated or done anything. It is very sporadic.

[Sir Osis of Liver]

You are running an older version of TP.  Couldn't hurt to upgrade -

https://custom.simplemachines.org/index.php?mod=97

[skb]

Yes. I'll be doing it. Thanks.