I have not seen any data on using dimmable LED bulbs and the XPDF.
The XPDF installation sheet says incandescent only and 40 watt minimum bulb wattage or it may flicker. Sounds like it may have local control sensing in it. It also has soft start where it ramps on and off.
Any reason you want the XPDF and not the XPFM model?
You may want to wait and see if other users can give you more information on what they are using.
Your country is 120 volts?
I know that Toshiba now makes dimmable led bulbs in all shapes and bases. I have no data on compatibility with X10 dimmers.
http://www.toshiba.com/lighting/group_display.jsp?id1=42I have seen some of the Philips LED bubs also listed as dimmable but not all of them. You would have to read the specifications sheet to determine if it is dimmable.
I know here in the US Homedepot sells EcoSmart LED bulbs that are dimmable.
I have an 'A' style shell one that seems to be OK with three wire dimmers like the Insteon SwitchLinc dimmer and X10 LM465 modules, but not with the ones that steal power through the load like a WS467 or WS12A.
The bulb in your link will not work with a dimmer switch. It is a universal power type that can use from 100 to 240 volts. I would consider any LED bulb as NOT dimmable unless specified in the specifications sheet for the bulb.