SendKeys Method, Vista 64-bit

I have a macro that works in 32-bit XP, but hangs up in Vista64-bit. The place where it gets stuck uses the SendKeys method totransmit a shortcut key; this was necessary because the add-in I amusing does not have an API call for this particular command.
In Vista 64 I have found that sending the key works, but only if Ileave off the portion of the command that determines the delay
SendKeys (["string"],[Delay])

So the problem is that the action I am calling with the sent key,takes several seconds to complete. Since the code will keeprunning, absent a programmed delay, I end up never seeing thecompletion of the action I am trying to take. Worse; the macrocalls this action 170 times, with several steps between each.

Do any of you have any ideas about how to work with SendKeys inVista 64? Is there a simple command I can use following SendKeysthat would pause execution of the code long enough for my commandto execute? (Delay 15 seconds, kind of thing).

Thanks in advance for the help!

DanielleSolidworksApi macros