Canon rebel XSi question

[serenitydawns]

Santa brought me a new camera..yippie!!!

BUT...I'm having trouble in manual mode. Reading Understanding Exposure, I want to try to mimic some of the settings - fast shutter speeds with large apertures (i.e. 1/1000 and f/2.8)

I can get those settings, but not with the flash on. With the flash up it limits me to 1/200 and usually around f/5.6.

Is there anyway around this?