Do you download a METAR?
If so then check the following:
1. Control Panel > Summary Images & Icons > Icon from METAR > Tick "Your station's rain/wind/fog overrides the METAR" and untick all other boxes on this page.
2. Control Panel > Units & Other Settings > Rainfall Setup > there should be no tick in "Ignore first rain of the day (dew in gauge).
3. Control Panel > Units & Other Settings > Weather Icon Setup > METAR to Set Icon > no ticks an any box other than "Your stations rain/wind/fog overrides the METAR" - this should be set when you set #1 above but check it anyway.
4. Control Panel > FTP & Connections > METAR Download > Tick in the box marked "Do not use the rain from the metar.
That's all I can think of at the moment.