I don't know if it is to difficult or not, but there's my sugestion:
In the "Last Post" column, there is the information about the last user who posted something and the date when that occurred.
So, could you add one more information to that column: the last thread where has been last posted
What i mean is: for example, you last posted on a thread called "Mod +", and in that column ("Last Post") this next information is shown:
This information could catch the atention of many potential users to the forum and the users themself, because thread titles catch the users atention.Last thread: Mod +