I'm going to need to see your code then, in order to be able to troubleshoot this further.
You can not create a thread in Visual Basic 4/5/6. Doevents is only a partial fix to your problem. Doevents tells VB that a long ass loop is going on, and that it needs to do other stuff too, like handle mouse clicks. So, just for example, make a form and put 2 buttons on it....in button1, put this:
while 1 = 1
x = 200 * 200
wend
Then, in button2, put this:
Now run the code, and click button1. Now
Try to click button2. Nice Huh? Now modify button1 to have this:
while 1 = 1
x = 200 * 200
doevents
wend
Run the code, click button1, now click button2..... oh wow. Big difference.