problems with the categories file in admin page

[pantufas_online]

Hello!

 

i'm working with 2.2 version, and when i insert a product it gives me this...i select de tax rate i have...and then a insert my price for the product, and when i finalize the process it automatically insert plus 20,70 eur (in my case), which is not suposed :(

 

 

i don't have any idea...does anyone knows, or happened to you?

 

thanks :)