Probably two things going on here. First, of those 10 widgets, about half probably use data and will refresh after each screen lock.
As far as the launcher pro reset: this goes to the functionality of the android os. When you are doing heavy graphics use, the os dedicates the processor and ram to accomplishing that current graphics intensive task. What it is likely doing is dropping launcher pro and your widgets out of background memory to free that memory for your graphics use. Once you come back to the homescreen, it is having to relaunch from not being stored in memory, hence the lag.
To fix the lag, go back to your stock launcher and remove any widgets you may still have on those screens. Even though the launcher is not being used, those widgets will still be running. Next, try reducing your widget count on your home screens, if you can. Third, set the refresh time frame on widgets such as facebook updates, twitter, etc to a time based rule instead of on phone wake-up.
Let me know if these things help.
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