hp prime simple integration doesn't work right...

[webmasterpdx]

I've posted this already but haven't received any help.
I was trying to do a simple integral from 0 to infinity and it gives me a cryptic message I don't understand about antiderivatives. It gives me the correct answer when I click on enter a second time as long as I do an assume(a>0) first.
Here are the screen captures....
here is a collection of screen captures....attached below.
1. first time run assume(a>0) followed by the integral.
   
2. After hitting enter, the cryptic message.
   
3. Hitting enter again and getting the right answer of 1/a.
   

is there some commands i need to enter first apart from the assume to make this work without the cryptic message.
Thx
-D