bf mobile on nokia e72

hi to all of you, i'm sorry for my englisht
i have a question for you, can i place a stake bet on betfair mobile for example 2.5€ or 4.60€, not only rounded stakes (2€ 3€ 4€)?
i can't make it, on e72 i have to hold button at the bottom left and type 1 2 3 4 5 6 7 8 9 like it was a normale phone (and not a qwerty) for login. in placing bet i can modify back or lay with dot (typing the same button and #) but in stake i can't, the dot does not appears.. why
the betfair service tells me that it's possible
many thanks
bye