Security - enter text question

but I have to enter the security text everytime I respond to a post , even if it's been 2 or 3 minutes since my last response . Is this a new security measure ?

Also , I cut and paste the security code . But now when I do it , the last digit is left out . When I try to manually input the last digit , it won't go in . Is that another security thing ?

Thanks for any help .