Flickr seems to have that issue a lot, which is why I never use it. LOL. 

The modify button will always be in your post to use, no matter how much time has passed. As a rule of thumb, if it's been less than 24 hours and your post is still the last one in a thread, then use the modify button. If more than 24 hours has passed, then it's OK to hit reply.

First: our site rules clearly state your images may not be larger than 600 x 600, so they have been removed. Please resize them.

Second, do not reply to yourself; use the modify button. Your posts have been merged. Even better, modify the first post of the thread with the images so the pictures will show up there without people having to scroll down to look for them, please.

Edit: I removed the img codes from your first post so people can just click the link to view them.