INCOMPATIBLE_MODE_ERROR

Hi everyone!
Sorry for posting in this group but there's no group for v6!
I need to do some actions on about 50 files.
But always I get error 88(INCOMPATIBLE_MODE_ERROR) on first few ones.
Then I changed the code to try as many times as needed to get a no
error result.
Now I always get 88 on the 1st file and operations on other files are
done with no error.
I know this error occures when a file is opened in 2 different modes
but in my code
each file is opened , processed , closed and then the next file.And
all in normal mode.
I'm working with Microkernel 6.15 on a single WinXP machine,not a
client server system.
And obviously I can't upgrade.

What should I do?
Can anyone help me.

Thanks.