This is a good question. Of the following Lexicon's, only the Liddell-Scott has "presume" as a possible translation. Louw-Nida has "to reckon something as being worthless" which could be short hand to say "presume" but in that entry it cites Rom 2:4 to mean "contempt for (God's) patience." Gingrich cites Rom 2:4 as "Entertain wrong ideas about" which maybe short hand may mean "presume". Below are a few different entries on καταφρονέω (taken from BibleWorks 8)
###Friberg Lexicon 15404 καταφρονέω fut. καταφρονήσω; 1aor. κατεφρόνησα; (1) as treating with scornful contempt look down on, despise, disparage (1T 4.12); (2) as treating with neglect disregard, slight, despise (HE 12.2)
###Louw-Nida Lexicon 88.192 καταφρονέω: to feel contempt for someone or something because it is thought to be bad or without value - 'to despise, to scorn, to look down on.' καὶ τῆς μακροθυμίας καταφρονεῖς 'and do you have contempt for (God's) patience' Ro 2.4; ὁρᾶτε μὴ καταφρονήσητε ἑνὸς τῶν μικρῶν τούτων 'see that you do not despise one of these little ones' Mt 18.10. In a number of languages the equivalent of 'to despise' is 'to think that something has no value' or 'to reckon something as being worthless.'
###Liddell-Scott (Abridged) Lexicon 23233 καταφρονέω f. ήσω, to think down upon, i.e. to look down upon, think slightly of, τινός Hdt., Eur., etc.
2. c. acc. to regard slightly, despise, Hdt., Att.:-Pass. to be thought little of, despised, Xen., etc.
3. absol. to be disdainful, deal contemptuously, Thuc.
4. c. inf. to think contemptuously that, to presume, καταφρονήσαντες κρέσσονες εἶναι Hdt.; καταφρονοῦντες κἂν προαισθέσθαι Thuc. II. c. acc. rei, only in Ion. writers (cf. κατανοέω), to fix one's thoughts upon, aim at, Lat. affectare, τὴν τυραννίδα Hdt.: also to observe with contempt, τι Id. Hence καταφρόνημα
###Thayers Lexicon 2859 καταφρονέω, καταφρόνω; future καταφρονήσω; 1 aorist κατεφρόνησα; (from Herodotus down); to contemn, despise, disdain, think little or nothing of: with the genitive of the object (Buttmann, sec. 132, 15), Matt. 6:24; 18:10; Luke 16:13; Rom. 2:4; 1 Cor. 11:22; 1 Tim. 4:12; 6:2; 2 Pet. 2:10; Heb. 12:2.*
###Gingrich Lexicon 3539 καταφρονέω—1. look down on, despise, scorn w. gen. Mt 6:24; 18:10; Lk 16:13; 1 Cor 11:22; 1 Ti 4:12; 2 Pt 2:10; Tit 2:15 v.l. Entertain wrong ideas about Ro 2:4; 1 Ti 6:2.—2. care nothing for, disregard, be unafraid of Hb 12:2.* [pg 105]