hi nial thanks for your ansers
double click seting normal
its not to do with move to fast i cheked this by lowering mouse speed then moving mouse over snap point and then cerfuly lifting mouse so that it is still on snap point but not on desk so can not move then click mouse , i did this for 2 point in a row after typing di i got no dimention in my command bar but after cliking a 3rd time i get dimentions
iv had this problem be for in the past