Almost every time, this issue is mismatch between item title you have entered in your eBay listing and product name you have in E-junkie admin. Now, sometimes you can not "see" the difference as mostly it's because you have put double spaces between few words or space at the end in your eBay listing. To avoid this issue, make sure you copy the title from E-junkie admin and paste it in your E-junkie listing.
If that's not it, confirm the following:
- Currency of the product in E-junkie admin is the same as the currency of the product in E-junkie listing.
- PayPal email where you are accepting payments for your eBay listing is same as the PayPal email you have entered in E-junkie admin > Profile.
- IPN settings you did are in the PayPal account linked with the PayPal email you entered in E-junkie admin > Profile.