Centered Content Becomes Un-centered After Editing

I don't know if there is a ticket already open for this, but I couldn't find one.
 
Basically my problem is this - whenever I edit the content in either of my custom content blocks(both of which have all content in them centered) and save the changes, the content returns to its default position on the left side of the content block. I can go back in and center it, save changes and everything is fine until I edit the block again.
 
Simply switching to BBCode mode un-centers all of the content also. When I manually type in the code to center it in BBCode mode everything is centered until I go in to edit it again, which un-centers everything.
 
I don't know if this problem applies to the forum also - I've only seen it in the Blogs.
 
So my problem in a nutshell is that editing my content blocks un-centers the content in them. Does anyone know how to fix this? Also, has anyone else encountered this problem? Thanks in advance. =)