What are you using too look at it?
My Webpad and Mozilla Firefox both show it right.
However, i believe you can force even faulty working ones to make it look right by using Tables
Code:
<TABLE BORDER="0">
<TR>
<TD>0</TD>
<TD><RADIO BUTTON></TD>
<TD>1</TD>
<TD><SECOND RADIO BUTTON></TD>
...
</TR>
</TABLE>
This will also give you possibility to center those buttons and so on.
Just remember to make Table broders and all "0", or otherwise they are visible.
There are also commands for those <TD>to give them more space between borders, even in case 0, to give you more control of the look.
edit:
Actually, a little outlook control tip.
Put one empty <TD></TD> cell between each number-radiobutton pair to make some space between them.
You can then use <TD WIDTH="20"></TD> for example to make there some space between those pairs and make it more clear looking.