[MacDV] Help converting to 16:9

[Desert Sun]

hello everyone,
i'm hoping someone can help me..
i have .mov clips (average 80mb in size) in the 16:9 format - 5 to 8 
minute shorts i downloaded off the internet - i'd like to burn with 
idvd 4. however, when i import them to idvd 4 and preview the project, 
they don't keep that same format. they fill the whole screen thus 
distorting the movies.. is there any way i can convert or save them in 
16:9 before importing them into idvd 4 in order to maintain the same 
format?
if anyone has any suggestions it would be very much appreciated.
thanks.

danno