Are you placing the start marker in your level.
Use the Green one.
If not then when testing a game it tends to drop you on the map at the last place you were, when you exit the map.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit, Screen resolution 1680 x 1050.