I had tried replying to this yesterday, but the forum was broke and kept saying page missing on replies. I had saved my reply text to not have to type it again and modified it slightly since now you resolved it:
Windows is pretty good about converting what is needed...although a few IE versions had a Rich Text bug and copying from forums and such didn't work too well. It is more likely that the other apps weren't closing the clipboard properly, some type of glitch didn't close it properly, or some other issue that rebooting fixed. I actually wrote a clipboard viewer app in PowerBASIC a few years back. I copied text in B4A and opened it-
1. B4A properly released/closed the clipboard and the current owner was the Clipboard Window/Class.
2. B4A Placed data in multiple formats for other apps to read from- TEXT, OEMTEXT, UNICODETEXT, LOCALE Data, DataObject, Ole Private Data, Rich Text including colors and formatting (Not just emulated from Plain Text), and System.String (Not sure what this is, might be internal to B4A).
I have WinXP 64bit at work and Win7 32 and 64 bit at home, and none of them have had issues with clipboard. Whatever the issue was should not have been caused by B4A.