[cvsnt] Preserving execute bit for checkout on Linux machines?

[Koen]

The problem:
I have checked in files from a windows machine, and these files should have
execute permission when checked out on a Linux machine. Now, I tried making
a very small difference and then comitting the file again on a Linux
machine, but still the execute permission is not preserved (the commit
*does* happen).
I read a few things already about problems with execute bit etc.. but never
found a solution.

The question:
How can I keep the execute permission for Linux files?
And how can I make a file executable after I had already checked it in as
non-executable?
I'm using pserver with Windows2000 and Linux RedHat machines.

The desperate guy:
Koen