debugging impossible exception

[vijay srikanth]

Hi,

Some times, when I execute work items of standard transactions like VA01, 
VA02 etc. I put break-points in the standard code, to see if some variables 
are getting populated the way I want them to. But because of this, when I 
execute it through the workflow I get the Debugging Impossible Exception 
sometimes. Can anybody tell me why that happens?

Regards,
Vijay