OK, so I think you can apply for Naturalisation say nine months after you got back to the UK. So look at the actual date in June 2005 and then apply on that same date in the month but in March 2006.
If you apply before March 2006 then you will be asking, in effect, for a discretion to be exercised in your favour. Have a read of
Annex B of the instructions given to IND staff dealing with naturalisation applications. In particular go to no. 5 of that Annex.
Firstly your absence from December 2004 to June 2005. Do an accurate day count. How many days outside the UK not counting the day of leaving nor the day of arriving back. 180 days or less? Or more than 180 days?
If 180 days or less then you might consider applying in October 2005, after you have had your ILR for one year.
Why might this be a good idea? Because any applicant for naturalisation received by IND on or after 1st November 2005 will need to enclose a pass certificate for the new Citizenship Test. But if you apply in October 2005 then you will not need to worry about that, but will instead need to consider the language aspect.
But do have a good read of no. 5 of Annex B. In particular the future intention to live in the UK.