I have a suggestion, which is to make a button that clears your inventory. It should be easy enough for you to make, and it really comes in handy! Unfortunately, there's only 7 save states... So could you make this button and clear up 1 save state for me? Good job so far. I'm using the 1.4.5 pre-release version. Although my previous post wasn't addressed by anyone (so I stopped using the mod PortalGuns).
By the way, it's working with Forge for me (1.4.4) just fine - I installed Forge and then put TMI over it, since Forge includes the inventory GUI class (but doesn't seem to do much with it). Unlimited stacks work too. If you install Forge on top then TMI won't load. Is there any other problem people have been having with this combo?