Lastinv makes SG/Dispensers disappear before building

When you are an Engineer and you switch to your SG or Dispenser, the pre-built models disappear and so does the warning that looks like a red 2 with a line through it when you use your 'lastinv' button to switch weapons.

Demo: http://www.mildsclan.com/engi-bug1.dem

I'll give an example. If I am playing Engi on D, I have my SShotty out and decide to switch to my SG to build one. An enemy runs in, so the quickest way for me to cancel my SG mid-build and switch back to my SShotty is the 'lastinv' key. Once I kill the enemy, if I then use the same key to switch back to my SG, the pre-built model disappears. If I then switch to Dispenser, it's also gone. If I already have a SG built, the same thing happens if I go to SG, switch back to a previous weapon, then switch back to SG again where it would normally show that I already have a SG/dispenser built.

Just watch the demo if any of this is confusing. I tested this in the BETA as well and the same thing happens.