You might want to take a look at my white paper: http://msdn.microsoft.com/library/en-us/BTS_2004WP/html/956fd4cb-aacc-43ee-99b6-f6137a5a2914.asp?frame=true&_r=1
I thought I am using a delay shape inside a loop. If it isn’t in the sample code then I did it in one of the samples on this site.
I don’t think it should be a problem. But, maybe your timer isn’t working right?
Hope this helps.