This has happened to me a couple of times using TextMate (probably has occurred elsewhere without consequences that I noticed). Every once in a long while, I will not be able to copy text into TextMate. I do this on a regular basis to analyze XML and JSON responses from the server for the application I work on at VmWare, copying FireBug response data into TextMate running either the XML tidy or a script I set up to tidy up the JSON data, so copying into TextMate is very important to me. Sometimes, however, it just doesn’t work. I can copy/paste in TextMate, but not from another application to it. As it turns out, this has to do with the system pasteboard server. Essentially, you can fix the problem by restarting this service. See: http://wiki.macromates.com/Troubleshooting/CantPaste for more details.