In case SAP thinks that some transport requests in STMS are still imported and keeps displaying the truck icon next to them, you might get frustrated.
The solution is simple though: Just delete the corresponding entries in table TPSTAT, and you are good to go.
This is a risky approach, though. If the requests are actually being transported, removing them from TPSTAT might trigger some unpredictable behaviour. If you are 100% sure that TP is doing nothing about them, you might try this little hack.