I had a kerfaffle with o2. As rightly pointed out by the esteem member that 0844,0845,0870 these nos do not come out from o2 long w/end allowance anymore, which used to be the case. on that note I went to o2 store in feb 07 and asked the exact questions, they said 600 - any time any network + thos 08 nos and 2000 long w/d the same.
second month £102 bill - shocked. straitaway called and asked. the member of staff did not fold and stuck to his gun. lots of rangling have gone and not they have offerred me the pac code, cancellation of contract and refund of about £65+ . when it happens i'll let you know.
but be careful they are aware of the int'l calls and t-mobile has already informed that 07744 will not be free from june 2007. o2 in a similar move have withdrew the 08 facilities since last week.
hope this helps