Can't nobelium form compounds like other lanthanides/actinides do? Over the past week I've been browsing through WebElements just to find out some interesting facts/properties about certain elements in the Periodic Table. 

I've just come across the uncommon element nobelium and it looks like it doesn't form compounds with anything despite being an actinide. For example, actinium can form Actinium Trichloride and promethium can form Promethium(III) Fluoride.

Is there a reason why nobelium is so 'special'?
Wikipedia reports that nobelium does form compounds, but unlike other later actinides it could adopt a +2 oxidation state as well as +3, which complicates identifying specific compounds (e.g. nobelium reacts with chlorine but the specific product is not known).  The +2 state is stabilized by the full shell configuration $[\ce{Rn}]5f^{14}$.  Experiments in aqueous solution seem to show a preference for the +2 oxidation state, and $\ce{No}^{2+}$ has been coprecipitated into solids.  But we have yet to definitively identify a neat nobelium compound in either specific oxidation state.