Digital Cameras - large flash memory cards ?

[mfds]

Anyone know if using a large flash card in my Canon IXUS V digital camera will slow it down ?
Say a 256Mbyte ? (very cheap now .... around £90)

I have heard some canon cameras 'check' the memory on power up and take up to 30 seconds ?

Do the larger cards take longer to download, even if only a fraction of the capacity has been used ?

I have heard the larger cards can be quicker due to the technology involved ?

Thanks