This will also only work when you compile with API version 5 and above, also, devices do not have to honor the request
In Java I used to use the setThreshold() method to set the number of characters+1 of the input length that must be entered before a prediction is made. But I don't think this is exposed in B4A? Maybe Erel can answer that.
Mahares Answers: It is still showing suggestions even with an edittext on Tab2 OS4.1.1. I even changed the SDK from 4 to 10, but it did not help.
I tried a tablet with OS 4.03. it works properly (no suggestion) with an edit text and an inputext dialog box.
Unfortunately the gregmartin64 suggestion of using setThreshold won't work as it applies to the AutoCompleteTextView type and not the EditText type used by Basic4android.
However EditText1.InputType = 144 seems to work on my Xoom. 144 is InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD. You could also try 128 which is InputType.TYPE_TEXT_VARIATION_PASSWORD and has the same effect as 144 on my Xoom.