COM8 supported / TBedit CPU load?

Hello all,

having TBsilver and COMLIB, I tried to open COM8. It's a virtual comport on my machine, created by an USB driver of an external ADC card.
NOT working!

I used another USB connector, and the data card appeared under COM5 then.
All fine now!
Question: does TB and COMLIB support Com8 or maybe not?

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TBedit causes more than 60% CPU load on a 2 GHZ machine. Keyboard autorepeat is much slower than in notepad, and if I type quickly (well, as usual), about 20% of all typed characters are 'swallowed' (lost).
Any hint how to overcome this problem?
Thanks in advance!
Brgrds
Fred