Gareth,
Had exactly the same problem as you. It looks like the problem lies with the specific computer or laptop you are using. I have a Toshiba Satellite laptop that will not download or upload data. There is another thread about this at:
http://www.rebreatherworld.com/inspi...d+communicator . Unfortunately, I found no answer to the problem, the downloading was quite erratic, I would get to about 5% on some tries and even got to 85% at one time. I spoke to Tony at the factory about the problem, but he did not have a solution. The only known problem with downloading is low batteries in the unit, I changed mine with no luck.
I tried downloading with my mates Dell laptop and it did it no problem, first time. I then tried it with an old Compaq Pavilion laptop and it worked no problem, both downloading and uploading.
I think it's like Rod said, some USB's don't give enough juice to the seirial / usb adaptor and it looks like it's machine specific. You could try pressing CRTL, ALT & DEL keys at the same time, press Task Manager button and then press the Processes tab, look for APD Communicator process, highlight it click the right hand side of the mouse go to Set Priority and choose Real Time. It will give you a warning but press Yes, this will give the APD Communicator priority over other processes, using this got me to 85% once.
Speaking to Tony at the factory, apparently you have got to get to 100% before any files are down loaded, it's sort of all or nothing. You will also see the handset read out change from PC LINK 1 through to 3 as it extracts the information form the controllers and handset.
For me it is not too bad, I can use the old laptop on a dive boat, if it gets washed then it doesn't matter, I just need to get another battery for it as the original died years ago
If you are still having probs, then I can have another crack at it. I will try and compare the settings between the laptops that work and the Toshiba that doesn't.
Cheers,
Leon