Title say it almost all.  Minor bug, but one all the same for custom races built on the Generic Tech Tree.  It's also a bit more problematic for folks creating a custom race, as the Tech Tree section of the Customize Civilization screen will display "Terran Tech Tree - A balanced tech tree" twice. Once for the actual Terran Tech Tree and once for the Generic Tech Tree.

The bug is occurring because the TechDefsText.xml file is saying:

<StringTable>
<Label>GenericTechTree_Name</Label>
<String>Terran Tech Tree</String>
</StringTable>
<StringTable>
<Label>GenericTechTree_ShortDec</Label>
<String>A balanced tech tree.</String>
</StringTable>
<StringTable>
<Label>GenericTechTree_Dec</Label>
<String>A balanced tech tree.</String>
</StringTable>

as opposed to what it used to say:

<StringTable>
<Label>GenericTechTree_Name</Label>
<String>Base Tech Tree</String>
</StringTable>
<StringTable>
<Label>GenericTechTree_ShortDec</Label>
<String>The base tech tree.</String>
</StringTable>
<StringTable>
<Label>GenericTechTree_Dec</Label>
<String>The base tech tree.</String>
</StringTable>

====

This looks like it slipped in during the 1.6 update FWIW.