I noticed that if I tried to post anything without doing the 'preview' option first, that it was giving an error about the post not containing enough characters even though it did have more than enough.

Not sure if anyone else was getting this problem but I was able to find the issue and solution after looking around the vbulletin forums. For some reason the WYSIWYG editor was causing it so I just had to set it to use the standard editor in the forum settings.