A ttyrec produced on one kind of terminal will not play properly on a different kind of terminal. Most modern terminals are similar and should produce compatible ttyrecs, but you might come across a file that won't work.
Replaying also might not work properly if your terminal is a different size from the one that produced the ttyrec. If things are getting drawn in the -wrong places, try making your terminal bigger. Unfortunately, ttyrecs don't tell you what the proper size is.
-(But it can sometimes be deduced, if you don't mind poking around with a hex editor. Check near the beginning for the sequence -[1;r )
+wrong places, try making your terminal bigger. +Unfortunately, ttyrecs don't contain any metadata which could tell you what the proper size is. But most recent files from the Gallery and similar sites +work around this limitation by putting some invisible text at the beginning. You can read it by opening the ttyrec with a hex editor or text editor. There +will be a line starting with "Size:" followed by the terminal width and height.
Note: if you are using ipbt, you must also tell ipbt what size terminal to use. Check ipbt's documentation.