Thai Dictionaries: Bug in the Software?

OK, here is the deal: Every time I try to use any Thai dictionary, e.g. Thai - Thai Royal Institute Dictionary, Thai - English LEXiTRON ™ dictionary v. 2, or English - Thai LEXiTRON ™ dictionary v. 2, GoldenDict slows down to a crawl using up to 50 per cent of CPU time, making any kind of meaningful interaction with the software all but impossible. Switching to a dictionary in any other language resolves the issue instantly. Is this a (un)known bug, or is it something that needs additional settings in one of the config files?
My copy of the software runs under Windows XP SP2 (English).
My copy of the software runs under Windows XP SP2 (English).