as -つかぬ in jawikt and daijr, as -つかない in daijs and 
jitsuyo
～も判らない does get a few hits though (on google books, 
6 vs 195 for -つかない)
At any rate, there's an audio file for this one so I'll 
make a new entry for つかない rather than change this 
one.

probably does't conjugate much but I think adj-i is helpful 
to explain the usage. (daijs example: 「始めたばかりで、まだ
―◦ない新商売だ」)

@@ -11,0 +12,2 @@
+<pos>&adj-i;</pos>
+<misc>&id;</misc>
@@ -13 +15 @@
-<gloss>cannot be foreseen</gloss>
+<gloss>hard-to-predict</gloss>