Computers are strange - well, I never believed in them being fully deterministic anyway.
mkk, indeed the problem only occurs when using the custom setting's clock tab, not the general in the CP. But what I like about RadlLinker is just the ability to kind of dynamically overclock - I'm using some TC fans in my case and don't mind (even don't notive) their noise at higher speeds when playing an FPS, but it annoys me when brooding over some piece of work. Removing and recreating costum settings didn't change anything for me (with one strange exception in the wrong direction, see below).
ChrisW, a fresh install didn't work either. And before installing the Omega package for the second time (after realising this problem) I used driver cleaner, hopefully correctly

. I'm reluctant to do it again, since the whole process is a bit tedious. But considering the time I experimented so far it might be well worth it.
I tried some other stuff, though:
1. The "normal" behaviour of the custom settings: As soon as I activate OC, after closing the properties window the value for Core Frequency is set to 0.00, the value for Desktop gamma Red is set to 5.53 and the value for desktop gammma Green is set to 9.27 (both quite senseless), the RGB lock is unchecked.
2. Installed the standalone version of RadLinker (1.014), which behaved the same, wexcluding the non-present settings for desktop gamma of course.
2. After searching my registry, I found some remnants of the Sapphire Game Utility, which I'd uninstalled quite some time ago. I deleted all entries I could find, which led to the following behaviour in custom settings: After applying OC it was set to 385.71 synced, the desktop gamma for Green was set to an absurd value with two digits in front of the decimal point (couldn't read the first one properly) and the game gamma for green was set to 20. The other OC utility I have formerly used and uninstalled is AtiTool, but I found no traces of this.
3. After un- and reinstalling, RadLinker Custom settings' behaviour got back to normal (as described in 1.). One moment of hope, though: The first Custom Settings I created worked properly! But after removing and recreating - well, see 1.
Since RadLinks themselves are working fine for me and actually give me all I need (well, RadLinkerwise, that is

), I've lost some of my enthusiasm to dig deeper into this right now. Maybe I'll try another full clean install of the graphics drivers tomorrow.
Btw, thanks for a faster (and often better, what I've read on these boards so far) costumer service than some comercial products have to offer!