Your overweight to start with if it's doing that.... think the threshhold is 40 below your max carrying capacity.
If it's casting a spell you don't have it might be trying to heal using chiv, will double check that the heal and cure subs are working properly.
If a script isn't working, try pressing F7 to start the script, continue pressing it until you get to the coding that you believe is wrong, then reply stating where in the script it is.
Actually, I found it, the heal subs weren't working properly. Should be working now. Please make sure your at full health before starting the script. If it still goes to first rune, then straight back to house to heal then increase the value of %TR_wait however this will then reduce the efficiency of the over-all script.
The other option is to wear a suit that DOES NOT have any +hp or +str on it. When you recall, it only takes your chars stats while naked, then re-equips your suit once you arrive at your destination. This means that your not at full HP when you get there. So the script is taking you back to a safe spot to heal you back up.