performance - My simple XNA game is slowing down for no good reason -

i made stupid simple xna game curious reason slows down. made fps counter , fps drops 60 2 in seconds. time drop takes inversely proportional number of "blocks" (simple objects) put on screen.

here tried:

• commenting out added basic game template (one one)
• making empty game project fps counter see if drop. did not.
• i installed indiefreaks game profiler no (picture below)

game screenshot while running profiler says game1.update using memory methods in using none. how can be?

also should mention besides simple game code im using project made earlier use of games. provides basic type game objects derive from, simple resource manager, collision detection methods, input handlers, kind of stuff. i'm mentioning because methods may magically somehow use memory.

so guess i'm asking common non-obvious reasons game slow down. or tips on can find out whats killing fps.

edit: hesitated upload code because "other project" mentioned above. bunch of uncommented code , have no documentation explaining how works, didn't want guys go through hassle of reading it. seems necessary here is, code: link

i included wormhole project (what mentioned before, thats it's called reason) guys can see code of that. assume references wormhole , indiefreaks game profiler won't work since not in same place on pc in mine. uploaded google drive can read code online. suggestions wormhole welcome.