Wait until June 21st is all I can tell you, unfortunately - we've already fixed the bug (or worked around it, it's actually a bug in OS 4 that Apple doesn't seem to have gotten around to fixing), and we'll be submitting an OS4-compatible version of Pleco to Apple the first day they start taking OS4-optimized app submissions, but that version likely won't be available in iTunes until the 21st. If OS 4 weren't coming out until July we probably would have put out an intermediate, non-OS4-but-fixing-this-bug release before then, but with OS4 coming out so soon we didn't want to have to go through a second update immediately after that first one to enable OS4-specific improvements like multitasking and high-resolution icons.