My shimano curado 300e is a very good reel.  Problem though is with braid it winds the line high in the middle not evenly across.  With mono it's perfect.  

Using 30 and 50 lb power pro. Do I need better braid or is it the nature of thos higher capacity reel. 

It;s not the nature of the high capacity reel or the braid that your using. Is it getting so bad in the middle, the braid is hitting the frame?

Did you over fill it with braid?

Pic would help...

 Usually about half full(when spooling)  I notice it beginning to mound in the middle.  I have no pic because I have just been using mono or backing with half mono then braid to get better lay from the braid. I really wanted to run a full spool of braid but cannot.  

Fill it up with braid and go use it on the water...Bet your problem will be solved.

Or go to the park and tie to a tree, let out as much line as you can. When you reel in make sure you have plenty of tention and, aim the rod tip at the tree.

is your connection to backing knot too large and in the middle?

I have fished with it with the braid on it stayed the same.  I have taped the line on before spooling to avoid a large knot and spooled under very tight tension. Oddly if I use mono there's no problem.  I'll try it all again using the suggestions maybe I overlooked something but I have tried several times 

The reel is awesome with mono does anyone have a 300e and braid brand suggestion? 

good suggestion/question from iabass about the connecting knot.  i've had that happen before and would make the line do some weird stuff on the spool.

I did fool around with the connecting knot.  I put it to one side instead of the middle and tied a small knot. Spooled the line with adequate tension.

This worked thank you everyone