Error: DOMDocument::load()

Hello all,

I’m having a little problem, I have these result:
http://oceanicowebprojects.oceanicogroup.com/real_estate/properties.html?nat=2,157&ctr=&stt=1,3,4&pg=1

but if I do F5 many times my page show an error:
Error: DOMDocument::load() [domdocument.load]: Input is not proper UTF-8, indicate encoding ! Bytes: 0xE7 0x61 0x3C 0x2F

Please can you help me?

Thanks