i don't know.
if you are using some software packet-writing such as InCd, Drag-To-Disc, maybe someone would know if it can be fixed or there's some setting.
if you are indeed using Window's built-in burning capability (bad bad IMO) i don't know anything about it.
AFAIK when you burn (with an app like Nero, not when you packet-write) to CD-R or DVD-R the files become read only.
just tested with a DVD+RW had lying about, same thing.
CD-RW same thing most likely.
i don't know about packet writing if the same happens nor Window's burning capability.
re Window's burning capability - i don't think that's packet writing. i think it buffers the data and at some point burns it (just like a burning app such as Nero). so it would be just like i said - the files become Read Only and you can't change that with right-click -> properties.
my guess is that when using packet-writing the files don't become Read Only (that would be silly for packet writing), so it appears that's not what your'e doing.
what's the big deal about having the files marked Read Only ?
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien