I wonder if there is a limit to the amount of files uploaded? I do know they are stored in your user control panel under >front page>Manage Attachments. You are able to view them and delete them as desired. You may want to try to delete some of the older ones then try to add a new one again in the post you are not having any uploading success in.
Just a refresher here and for any newbies out there: Uploading images you must click choose file first and select a file from your computer you wish to upload. Then Click add and it will upload to the forums memory. Then you click where you want the file to appear in your thread message. Then click the button below which says Place inline to add it to your threaded message.
Just some Thoughts!
Facebook: Hogan's CNC Crafts Website: www.hoganscnccrafts.com V-Carve Pro 9.518
try reducing the size a bit more, I know the blurb says max size 2mb but for some reason it will refuse jpeg images that are smaller than that sometimes. Often for me just making then a little smaller is enough for them to upload