Make sure that your Listing activity and Activity log are both erased. Then reboot your computer and start TL and begin the import. The answer to you question is there is probably a limit, but I have never reached it. The most I have imported is about 28,000 listings. That was approx. 30 days of listing including everything sold and unsold. The limit is not so much about how much you import...... its about how clean your Turbo Lister is, the speed of your computer processor and the amount of ram you have. You need to be very patient with TL. Once you start the import do not touch the computer until its finished.......ie do not use it for other things such as surfing or checking email.