Question : Problem: Help wireless signal to Media Center is very low

I have a Vista Ultimate Media center box that I keep upstairs
and my xbox 360 is connected the tv downstairs when I try to get the media center extender to work on my xbox 360 it says that the signal is too low for standard def tv so I want to boost the wireless signal or try something else going?
would a wireless repeater make the signal better? or would getting larger antennas be a better idea?
and what would be the best cheapest one to get and use with my linksys wrt54g

Answer : Problem: Help wireless signal to Media Center is very low

The antennae by far would be the easiest to test....Although the WRE has a one touch config, I have found that in some cases I had to log into it and configure manually....