Hi Tom Many thanks for your reply to my problem also thanks to Peter and David. I have 2 computers :- my desktop machine is Windows XP, processor - Athlon 64 3000, Graphics card is Radeon 9200 with 128 MB Ram Computer has 1GB DDR Ram. My laptop is also Windows XP with Intel Core 2 Duo T5600 1.83 GHz processor, 256 Mb Nvidia GeForce Go 7300 graphics card, system Ram 2 Gb DDR. I have tried turning Hardware acceleration of - this makes no difference on either machine. Iget identical results on both computers. I do'nt think I have a systems problem. If you can come up with any ideas I would be grateful. In the meantime I am going back to using 4.48 which gives me good results. I would like to be able to play around with the zoom and pan facility though. Thanks to all for your suggestions. Den Shelley