Hausman test of IIA - Interpretation

Dear all,

I tested my 2011 data for IIA and got this result:

qui mlogit outcomes $xlist [pw=pfwgtpop], baseoutcome(0) vce(cluster hh_id) allbaselevels
estimates store all
qui mlogit outcomes $xlist if outcomes<3 [pw=pfwgtpop], baseoutcome(0) vce(cluster hh_id) allbaselevels
estimates store no3
hauman all no3, alleqs force

Result:
chi2(50) = -44.07
chi2<0 ==> model fitted on these data fails to meet the asymptotic assumptions of the Hausman test

Doing the same for 2013, I get:
chi2(50) = 65.97
Prob>chi2 = 0.0645

And for 2014:
chi2(50) = 19.33
Prob>chi2 = 1.000

First, can anyone help me interpret this? From what I've read, a negative chi2 quite basically means that IIA is not violated. But what do positive chi2 results mean, and their P-values? Why didn't I get a P-value when I got a negative chi2? Do my 2013 and 2014 data also not violate the IIA assumption?

Second, this is the Hausman test for only one instance where I remove the 3rd outcome. Do I need to conduct it removing all the outcomes one at a time? Do I switch the base outcomes as well?

Thanks for your help!