About ten days ago I realised that data was not getting uploaded from my Garmin Forerunner 305 into the Training center application on the PC. On further investigation I found that the problem was actually different - my device had stopped storing data in its memory almost exactly 2 years after I started using it. I used the device for the first time on 4rth July 2007 and the last hirstory data in the unit was for 28th June 2009(my 11th FM in the current series). All data after that date was lost. As per the user manual the unit is supposed to overwrite history data once the memory is full. I tried deleting the history data but was unable to do so.
Having become addicted to my Garmin Forerunner 305 and uploading and analysing my workout data on a weekly basis I was quite disheartened with this malfunction of the unit. In despair I wrote about the problem to Garmin support and got the following response a few days later.
'Dear Bhasker Sharma,
Thank you for contacting Garmin Europe.These problems can usually be solved by updating or reloading the unit software and then performing a hard reset. Please be aware that this process will clear all of your data from the unit so ensure that if possible it is backed up to a computer.To update the software on the unit the Webupdater can be used, which canbe obtained from: http://www.garmin.com/products/webupdater/. Download and install this then connect your unit the computer. The webupdater will then check for available updates and download as necessary ? if theupdater states that you have the latest version then please select the option to reload current version.To reset the unit turn the unit off, hold down the mode button and turn the unit on. When the unit asks if you want to erase all user data, select yes. After resetting the unit, leave it with a clear view of the sky for about 30 minutes to acquire the satellite almanac.
If there is anything else I can help you with then please let me know. Alternatively you can search for a solution here: http://www.garmin.com/support.'
I followed the above instructions and downloaded the Webupdater software using which I updated the Firmware on my device from V2.6 to V2.9. Then instead of reseting the unit as mentioned above I turned it on and was prompted to delete the history data. I was able to successfully delete the history data and thankfully all is back to normal and my workouts are being stored again!