I had a set of RHA double flange silicon tips (http://www.rha-audio.com/uk/accessories/double-flange-ear-tips-medium.html) hanging around home so thought I'd try them on the GR07's on the off chance. They fit! Had them on for the past 2 weeks and find them very comfortable - don't slip off, well sealed and sound great. If anything I think they help seat the GR07's in the "well" of my ear a lot better than the foam tips and are much more comfortable for extended periods of listening. Fit is very much an individual thing but I think I've solved all the issues I had with my GR07's and am looking forward to a lot more usage of these great in-ears. If anyone is interested I'll put up some photos.