any luck sorting out your problem?
i wonder if there is some sort of "gunk" under your shutter release.
perhaps a light application of aerosol electrical contact cleaner directed under/around the shutter button might dissolve/dislodge any "gunk" interfering with the button making solid contact when depressed - CAUTION : here is where you could benefit from someone here with some experience and expertise in dealing with lubricating small electronic components. it might do more harm than good...definitely call a local electronic or computer or copier repair place and see what they think before you go splishin' and splashin' with any sort of cleaner around the shutter button.
another thing, i cannot remember for sure (and the SLX is home- have the 6002 & 6003 pro with me), but doesn't have two shutter release buttons?
if so, if you haven't already done so, you could try the steps you mentioned before using the 'other'
shutter release button...
best of luck.