We've never experienced that on any of our test sites.

It should look like this:

Bob posted a comment on the image Test Image

or

Admin posted a comment on the photo album Album 1

Make sure you are running an official release. The latest is 1.5.1: http://community.elgg.org/pg/plugins/tidypics/read/51273/tidypics-photo-gallery-plugin 

i think i am running the latest version .. will removing the plugin and reuploading and enabling it again removing any existing album data ?

No, it should not delete any album data (no guarantees though!).  Make sure you first disable it, then remove the entire tidypics directory on your server, and then re-upload and enable.

Removing a plugin and adding it back doesn't affect the database or the image files uploaded. You should be fine there.

You can check your language file in the plugin to make sure it is correct. In tidypics/languages/en.php, the string the activity plugin uses (from the river view) is

'image:river:annotate' => "a comment on the image",

I'm not sure how you are getting "posted %s commented on"

got it ... seems i had an older version thanks :)

@Tidypics Team: I think there is an issue related. In the folder views/default/river/object, there are views for album and images annotation, but I think they are never called. Instead, default annotate view is showed in the river. Then, if a commented image has no title, the river show "[user] posted a comment on the image". The image url is there, but as the <a> has no text, the link is missed.

The problematic language entries are related to the unused views.

Am I right?

Thanks in advance and sorry about my english.

@morgar - they are called in Elgg 1.2 but not in Elgg 1.5. In Elgg 1.5, comment river entries have been moved to the core.

I also find this irritating and have logged a bug with the elgg core.

https://trac.elgg.org/elgg/ticket/1044

@Tidypics Team: As I mention in my previous post, the 'custom' annotate view for images solves the issue, but as you say, it is not called in v1.5.