Yes, one more release of Managed Switch Port Mapping Tool v1.99.9.X. Since v2.0 is in beta I didn't really want to put out another release, but this was necessary. In fact, it was a beta tester who pointed out this problem and existed in both versions. It's actually not a bug, but more of a misinterpretation of the local network.
By default we activate the Ping Sweep function and prepopulate the Ping Sweep target table based on the computer's IPv4 address and subnet mask. That's all well and good if it's a 255.255.255.0 mask, but if it's a 255.255.0.0 mask as would happen in a 10.x.x.x private network, it creates a massive range of IPs that take forever to ping. The program doesn't hang, but it just takes a long time to deal with the range of IPs.
Now in v220.127.116.11 when you start a switch mapping, if it sees a large IP target range, you are given the opportunity to skip doing the ping sweep and continue on. You can always disable Ping Sweep or go in and change the target IP range.
Enjoy the new version: