After installing 1.0.13 beta, Warpin still shows 1.0.12. Is that intentional ?
Yes, it's 1.0.12.2. It won't be 1.0.13 until the GA.
Background: back in the past something screwed up my Warpin Database and that happened AFTER I installed XWorplace 1.0.12 but BEFORE I installed 1.0.13. It is possible that on installation of 1.0.13 there was no entry in the Warpin database for 1.0.12.
Nonetheless the side effect for the AMouse plugin installation remains: you will have to RERUN the AMouse plugin installation (deinstall and then reinstall) after installing XWP (to a different directory). Or fiddle around with files.
To see if there really was a problem, I did the following 3 times: I uninstalled XWP, reinstalled an older version in one of several directories, then upgraded to one of the betas (with a reboot in between each step). In every case, WarpIn forced the upgrade to use the existing directory, not a new one. You may have had a WarpIn failure, but I don't believe XWP was the cause.
Next time, you might consider reviewing the suggested installation directory and possibly changing it before pressing OK...