It's my negligence about avi overwritten bug in the recently version of PEnGUIn(Encoder).
Thanks our users of reminding me to fix it.
In this version, you can specify a output path for avi encoding when pressing launch of AVI encoding panel.
There is also a condition statement for preventing file overwritten.
Recommend everyone upgrade it.
Happy New Year!!
DOWNLOAD: PEnGUIn(Encoder) 1.3.8u