I have only used 2 mods.  In-Game NBTEdit and TMI.  Pretty certain TMI messed up the world save file with mismatched IDs.  How do I correct this?  How do I remove the mismatched IDs?

If it's a problem with TMI, I advise you speak to the mod author.

I've left a message there as well.  The problem is that if I load the map even with TMI not in the folder, mismatches get reported.  Someone has to know how to correct this.  Do I go block by block and replace the mismatched ones?  If so which ones are mismatched?  Is there a chart to determine mismatched IDs?

make a backup of your world then hit the 'continue' button depending on what's changed and if you've used them just loading the would may be fine. However if you used those items you'll have to reconfigure your modpack to make the ids sync up. This is done to prevent you from destroying your world if say you change the id railcraft uses for all of its blocks.

 

There is no true way to fix this as its a per case thing however the main recomendation is to edit your mld configs to realign your ids. And add the mods back if you removed that mod unless you KNOW that you didn't use anything from that mod in the world.