Man i just tried 800mb disks today. it burned fine with an LG52x. haven't tried burning on my SONY crx230e. I can tell u for sure that Liteon DVD RW does not burn nor recognize it. I HAD BURNED USING ALCOHOL after enabling overburn. I HAVE NOT tried with nero 6.3125.
Sony was reading the disk(about 750mb data) before but not now

. neither of the two disks

. Well.

I hope i didnt loose my Longhorn.
another thing, Nero will not recognize that disk as 800mb, it showed me as 702 but ull be able to burn it after enabling overburn to
exactly 90 minutes. i think the funda here is that on that disk the tracks are already conpressed. when u set overburn to 90 mins
not more not less the software will record exactly on the tracks of ur disk, cos thats how its made. so that mean. keep overburn setting to 90 minutes even if ur data size is 705mb or 775mb.
Also get a firmware upgrade for ur drive. Google it. THATS VERY IMPORTANT.