The wireless DS90 sensors work fine with RFXCOM. They operate at 433.92MHz and my RFXCOM has a 433.92MHz receiver. You can use them for just about anything that needs a simple On/Off sensor. The one thing wrong with them is the ridiculous price tag compared to the 310MHz version.
Fortunately, in the US, the DS10A (DS7000) can be found very cheap on eBay. Big John sells them in packs and ships to Europe. (Only takes a few days).