I use the v2.6 of Omars installer, and are having some of the same symptoms. The rightclick menu of steam - must be forced to stay up by a little series of fast clicks... that works for me.

Another issue is that, the "start bar" will show itself inside CS 1.6(steam). I narrowed it down to 2 things.

1. If I have any maximized windows it occurs (So I have to be fast and minimize before the game goes full screen(I use ASE to find my fun)).

2. If I have anything else selected in the bar with the CPU/ram stats - it will occur.

But it seems like omar has a new release out - so if that rectify this I will report back.

/EDIT:

So I tried the new OTS2 installer v2.9.5 by Omar, and I like it - works more smooth than the old one - hehe but the combination of HL, liteSTEP and the new 3.8 Catalyst are a funny mix, read on.

Now the topic of Half-Life based games; my experience is that HL v1.2.X.X(STEAM) will work IF you minimize all open windows before the game goes full screen.

HL v1.1.1.0 is another case, the game might go full screen if you DON'T minimize any of the windows but let them stay(that is not bullet proof but works 80% of the time).

Actually STEAM has proven to be the one least haunted by the bug... I hope that if we gather info enough it will make the solution come to us.

For them both I find it works best if the CPU stats etc are selected(I use simplicity).

On a side note I have tried shifting to other themes - but that have no impact!

And if i shift to explorer - the problem disappears.

well that's my input... geniuses I bow to U :)