What version of ActiveSync do you have on your computer?
I assume that you have had this device for a while and are not new to it. I am currently using version 4.2 of ActiveSync, which you can download from Microsoft, and rarely have any problems with it.
I would try doing a soft-reset on this machine, restarting your desktop computer. I would recommend uninstalling ActiveSync if you have an older version and installing 4.2, or even 4.5, they both seem to work well for me, and I rarely have problems. If this doesn't work, you can always do a hard reset on your 900, which is removing both batteries, waiting no less than 15 minutes with both batteries off, and then re-inserting the batteries and starting over. (Do this only if you have nothing you would regret losing, or if you have backed-up your data.)
I mentioned the hard-reset because it can often save you a lot of hassle of looking all over for the answer and then finding out that the answer you got gets you nowhere.
If you are able to, I would do a hard reset plus uninstall older version of ActiveSync and install either version 4.2 or 4.5 on your Windows XP or earlier machine, and then see if that works.
If that does not work, go to http://www.hpcfactor.com/forum, go to the section for Handheld PC's, and make a post with your problem and someone will answer. They are really good with these machines and can usually point you in the right direction.
Answers & Comments
What version of ActiveSync do you have on your computer?
I assume that you have had this device for a while and are not new to it. I am currently using version 4.2 of ActiveSync, which you can download from Microsoft, and rarely have any problems with it.
I would try doing a soft-reset on this machine, restarting your desktop computer. I would recommend uninstalling ActiveSync if you have an older version and installing 4.2, or even 4.5, they both seem to work well for me, and I rarely have problems. If this doesn't work, you can always do a hard reset on your 900, which is removing both batteries, waiting no less than 15 minutes with both batteries off, and then re-inserting the batteries and starting over. (Do this only if you have nothing you would regret losing, or if you have backed-up your data.)
I mentioned the hard-reset because it can often save you a lot of hassle of looking all over for the answer and then finding out that the answer you got gets you nowhere.
If you are able to, I would do a hard reset plus uninstall older version of ActiveSync and install either version 4.2 or 4.5 on your Windows XP or earlier machine, and then see if that works.
If that does not work, go to http://www.hpcfactor.com/forum, go to the section for Handheld PC's, and make a post with your problem and someone will answer. They are really good with these machines and can usually point you in the right direction.
Hope this helps
Regards,
elMono28