<p>It is really annoying.</p>

<pre><code>Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new mainForm()); &lt;-- pausing visual studio breaks here.
</code></pre>

<p>Thanks guys.</p>

@sramey are you sure pausing always breaks on the said line? If I may hazard a guess here I think when you press the pause button you application is idle and the program is spending most of its time in the Win32 message loop abstracted by Application.Run(). Hence there is a high probability that VS breaks the execution of the main thread there.
I think pressing pause is not always the best way of debugging things. You need to make educated guesses about problem areas and set breakpoints in relevant methods (like Constructors, API calls etc)
Need more info on what you are trying to accomplish here.