Setting style/skin for individual users via admin CP when users can't normally choose

[gef]

Hi!

I've run into a head-scratcher here.

I run a 3.6.5 forum (licence renewal and update imminent) here, and it has two skins - one dark, set to default, and one (mostly broken) test skin.

Users cannot select skins, so everyone is using the default.

Can I set specific users to use the other "test" skin? In the admin CP, if I find a user and edit their settings, there is a drop down for style, which gives me the options of default, the dark skin, and the broken test skin.

However, if I select the test skin, the user still sees the dark one. Logging out, clearing cookies etc doesn't work, the default is the default, despite their profile saying they are using the test skin.

I need a handful of members to use the test skin, but not everybody.

Have I missed a setting? Do I need to rebuild a database or something to force the change? Or, despite the user-specific setting change via the admin CP, does the disallowing user selection override everything?

Is there a way around this?

Many thanks!

Gef