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I think there might be...nothing concrete...but I think the DP1s and SD15 files are more closely related than the SD14...make sure you have the new Photomatix 4.0 ... I did not find anywhere where it states it supports the SD15...but it was only released 9/2010....
If you find more on this I would be interested in knowing..so please post here..
There is difference between files for sure, although DP1(s) files should be usable (at least in fixed WB modes - AWB/CWB data have different structure). Maybe Photomatix behaves like SilkyPix - images from all cameras not directly supported are just discarded.