Yes, I agree. From your evidence, this is classic Fuel Filter Syndrome.
Apart from getting at the filter as described in t
rikey's link, you'll need an 'FOC' (Fabled Orange Clip) to lock the filter together so it won't separate again. This requirement was covered by an MGR recommendation for all post-2001 petrol models to get the fix.
See this link for the details and HowTo:
http://www.mediafire.com/file/dwu9ob...%2529.pdf/file
TC