I also have the same issue, i recently installed Automod, ReIMG Image Resizer and edited files to make links open in a new window, i think one of the files edited in the image resizer mod is to blame, everything else on the board works:
What version of phpBB are you using? phpBB 3.0.7-PL1
What is your board's URL?
http://ww.unitylowriderforum.net
Who do you host your board with? parrallel plesk
How did you install your board? I used the download package from phpBB.com
Is your board a fresh install or a conversion? Fresh Install
Do you have any MODs installed? Yes
Is registration required to reproduce this issue? No
What styles do you currently have installed? SF_Glacier
What language(s) is your board currently using? english
Which database type/version are you using? MySQL 4
What is your level of experience? understand basic PHP and phpBB, defintaley understand the principles behind editing them
When did your problem begin? today @9:30pm after image resizer was re-installed after failure
Please describe your problem. Topic icons not working even though they are enabled?
The icons are also not visible in the EDIT image set screen from ACP ?? the icon selection name does not respond to any of the icons selectable from the drop down box