DVDR3300H Recording to Disc

I have a Philips DVDR3300H and until recently never had a problem with it. I have the latest software/drivers on it.

Before i was able to copy a 2hr movie from my HDD to Disc with no problem. But yesterday i tried copying a 3hr movie from the HDD to Disc and it now says not enough space on a blank 4.7gb disc.

By default by recording Mode is set to:- SEP

I have checked the User Manual and according to that i should be able to fit 8hrs of recording to a 4.7gb disc?

Anyone know why i am having this problem?

Thanks in Advance :doh:

Tanny