Just wondering why the forums now chop off the subject heading after a certain amount of characters.

Here's an example : 

Installing DotNetNuke : install problem - Doma...

The problem gets worse the longer the forum name:

Language and Internationalization : Re: How to...

I use the forum notifications to pick up on threads I might be interested in by scanning the subjects.  With the cut-off subjects it's very difficult to scan the list and get an idea.  It's just too time consuming to open and scan all the notification emails for forums you're watching.

Is this something we can change in our notifications profile?  Or is a site-wide setting?  Or is it just affecting me with my email?

The problem is the 100 character limit in the EmailSubject column in the email queue table. I wrote this over 3 years ago and this is the first time I seen it mentioned (not that it isn't valid Bruce). In a future release, I am going to have to move this to the new messaging in the core, which may or may not fix this (I haven't investigated the new messaging queue yet).