I have never been a Fusion Supporter, before building my HTPC, as usual I did an extensive research which included the upcoming APUs, but reading loads n loads if threads and experience I never was able to build the confidence to build an HTPC, around the AMD APU. Sure in a short run they perform, infact with SD hardly any problem. But when we start to push the setup with 1080 20mbps+ bit-rate or 3D or BRISOs, things do not shine that much. Its also correct that there was never a concrete evidence what could be the bottleneck, but it definitely didnt give any better impression.
I would always suggest to go for a dedicated CPU, Mobo, GPU. Be it Mini ITX, Mid ATX or Full ATX does not matter, but going with dedicated hardware would always be beneficial in future, specially if one takes the 3D route.
Anyway to the OP, did the problem resolve. What other measures you took to get this resolved ...???
BTW : You temp is not that I would be too careless about, its not hard summers, and that temp 68C is usually under full load in summers.