Copy Paste Issue

[Kryptyk]

A lot of you might have already seen this, but sometimes when I load up OS on another tab (I have two tabs open of OS, both with different MIDIs on them). I can work on both projects for a bit, right? Little bit of copy pasting notes from this measure and moving them to another on one OS tab, and then going to the other OS tab. I go to copy paste on the other OS tab, and instead of pasting what I just copied on the current tab, it pastes the previous copied section of notes from the other tab's MIDI. And I can't seem to figure out why or how to fix it. The only alternative I have is to use the copy paste buttons that OS has.

Any ideas on how to fix this so I can use Ctrl-C and Ctrl-V without having this issue?

Thanks ya'll!