Scrolling lag during draw
<p>I have started working on a new game using xna/monogame. I have designed a few 2D games before but decided to make this one isometric which is new to me. I have been using reimers isometric tile engine tutorial and most of the drawing code at its simplest level is a copy of this.</p>

<p>When scrolling around the map there is a stuttering on the screen which I can only describe as lag. I have put an FPS counter on and this stays at a solid 60 so I believe this is some kind of graphics problem.</p>

<p>I have tried commenting out sections of the drawing code to narrow down the issue but cant seem to make any progress, however this wasnt happening a couple of weeks ago so I'm confident its something that I have added, perhaps an issue with on the of the tilesets that's causing it?</p>

<p>Any suggestions are appreciated. I haven't put any code here as its turned into quite a large project and I don't know which area to concentrate on but I have uploaded the whole project <a href="http://s000.tinyupload.com/?file_id=47297466069786342879" rel="nofollow">here</a> if anybody is kind enough to investigate.</p>