I did a little internet research and I think this is a smart dialing issue. My Storm does not have a "Smart dialing" listing under Options or Advanced Options. This may be because I have a Verizon branded phone running on an American Network.
According to my research, you phone is dialing 1(242) automatically because it has been configured to do so under your Smart Dialing settings. I will attach a link to an article I found on the internet regarding this matter. Seems to me all you would have to do is disable this setting under Smart Dialing. Use the article to trouble shoot this issue. Smart Dialing Configuration | BlackBerry Cool
Let me know if it works.