VB.net 2003 debugging problem

Hi all, I have a strange issue within vb.net 2003.

I'm trying to step through some code within a project for example:

if txtpassword.text = "" then
msgbox "You must enter a password"
exit sub
end if

If I put a breakpoint on the first line, when I run the app the breakpoint moves to the third line. What's stranger is when I step through code within this project it even steps onto empty lines.

This is only happening within this one project. All of my other projects are working correctly.

Does anyone know how to rectify this

Thanks

Paul