Hmm. . . M'suggestion would be to backup any FH files ye wish to keep and reinstall FH. It could just be one of the many FH glitches that will occur over time.
Capitalization is key. Make sure to capitalize y'er usename correctly, 'cause someone else may be using Darkkythecat and exporting it as such will let floofs only see it on Darkkythecat instead of DarkkyTheCat.
When it makes ye export it twice, does it give ye copies (like DarkkyTheCat_9.fhp and DarkkyTheCat_9 (1).fhp) or does it only give ye one file. If ye upload the preset with the name DarkkyTheCat_9 (1).fhp and someone downloads it, the preset won't show up 'cause FH is looking for DarkkyTheCat_9.fhp.
If it is giving ye multiple copies, delete all copies except one and make sure it does not 'ave a (1), (2), and etcetera at the end of the file's name.
Let me know if any of these fixes help ye. If not, I shall try to figure out another explainable reason as to why 'tisn't working for ye.