Sony Ericsson Xperia X10 :: Poor Battery Charge / Can't Add Contacts To Address Book?

I was aware of the poor customer reviews of the x10's battery life, but it's turned out to be much worse than expected.

I will take the phone off of charge at 8am and ensure that no tasks or apps are running, not use the phone throughout the day, then by 3pm the charge level is around 30%. Often, if I don't start charging the phone at that point at work, the phone will run out of charge completely by around 4pm. I check throughout the day and tasks are not running, so how is the charge being lost so quick?!

This problem is not getting better: I read customer reviews saying that the battery problem improves after around the first month, but my case is the opposite - it started to get even worse after the first month!

I am also having a problem with adding contacts to the address book - all of a sudden it seems that I cannot add new contacts. I will add one contact, go back to the address book and see the new contact being displayed in the list, but when adding a second new contact both the first and second new contacts disappear. I do not have a problem with phone memory, I have tried saving to both SIM and memory, have tried backing up my address book in case that makes a difference, have switched the phone off/on again, but all to no avail. I have tried adding a new number to an existing contact and the new contact seems to disappear. It goes without saying that I have read the x10 instructions on this subject (and it goes without saying that I make sure to press save/done when adding the new entry).

It's got to the point where I am starting to regret choosing the X10. On the face of it, this is an excellent phone, but two relatively simple problems are ensuring that I feel like I own the poor man's smartphone (dare I say it, I wish I chose an iPhone now).

I checked with both my network operator and the shop I bought it from - unfortunately I am outside the 28 day initial period (I am in the UK), so the only recourse offered to me by the shop is to give me £20 to buy either a new battery or to buy a new cheap pay as you go phone so that I can return the handset/battery to SE. The problem with both options is that I am not confident that it will resolve the problem.

Anyone else had any issues like this?