Hi dubya
Sounds like LW set a new shared folder--search you hard drive for the name of a recently downloaded file or click on the shared folder in the library pane and use the explore button to find it.
The slow behaviour/force quit is not normal unless you have hundreds of pending downloads, and might indicate it's time for a general system tune up (safe boot/repair permissions/run software update/repeat/restart).
If that's not clear or you need the links for more info, post back with your system specs and someone might have more specific help.
btw--you probably wouldn't notice much difference with the pro--they're subtle. Free is really good--Pro is worth it though just to support the continued development of LW.