Mail/Clipboard disconnect

This is the 2nd time in just 2-3 days that I've had a really bizarre problem with the clipboard: it is not playing well together when going from PC-ish stuff to MacMail...

Today's problem: trying to copy some paragraphs from an Internet Explorer-accessed website on my windows PC (accessed via mac-> Microsoft remote desktop to my PC -> Internet explorer) to a note in Mail (on the mac), using ctrl-C to copy while in the remote desktop window, then going to the open message in Mail and clicking cmd-V, getting nothing to paste. Verified the info was on the clipboard by copying to a note in Outlook on the remote desktop. Able to circumvent issue by pasting into TextEdit, changing to plain text, copying/pasting from there to Mail.

Eerily similar issue the other direction: trying to copy an e-mail exchange into an open note in a program run in citrix desktop directly on my mac (ctrl-V), getting nothing pasting to the citrix desktop note, but finally solved the issue by pasting in TextEdit, converting to plain text, recopying and pasting to the kids note.

This is a new level of PITA for communication across platforms--I've had times before where I had to attempt copy/paste procedures more than once to get them to go, when I accidentally used ctrl-c or ctrl-v while on the mac side of things, or cmd-c or cmd-v on the citrix/PC/windows side of things but not like this until this week.

Mac is on 10.6.8, mail is 4.5 (1084).

Any thoughts?