Not sure if this is helpful, but this is the full error (I'm just learning firebug too):

a[j] has no properties
e(Object details[country]=840 details[zone]=33)jquery.js (line 2)
e(Object global=true ifModified=false type=POST timeout=0)jquery.js (line 2)
quoteCallback("2043%5ETong+Ren+Therapy+Model%5Eyyhtr1000%5E%5E1%5E17%5E25%5E15%5Ea%3A3%3A%7Bs%3A10%3A%22attributes%...")uc_quote.js (line 69)
setQuoteCallbacks()uc_quote.js (line 10)
e(blur )jquery.js (line 2)
[Break on this error] eval(function(p,a,c,k,e,d){e=function(c){return(c