I suppose that you want to exchange files with some newer phone, i.e. SonyEricsson. You can't fix it, the problem makes different irda speed in these phones.
No good. I belive that the problem is what g spot worte. Beacuse it's ok, if I send files from my laptop. The problem occurs when I try to recive files from SonyEricsson.
I've got this problem when try to send file from Sony Ericson T610/K500i to sl45. The problem always occur, but I can send file to Nokia and laptop. I think that maybe software of 2 kind of phones has conflict. I have a post about this some months ago, but noone give any solutions.