Yes that is an issue with a lot of software, and also with lmms
You can read about fixing it here:
https://lmms.io/wiki/index.php?title=LM ... een_Issues
Besides that, since you are new in Forum
Welcome Manhattan !
Here are all important links:
http://lmms.io/forum/viewtopic.php?f=1&t=4740
-A few rules and useful forum instructions