I tried it on both the emulator and my phone and got an exception on both on the very first try (and subsequent tries).
There's no InnerException set in the ApplicationUnhandledExceptionEventArgs, no message written to the output window indicating what it might be, and it's thrown from internal methods such that there's not even a disassembly available to see what it is or why it's happening. I did a screen cap of it, available here: http://yfrog.com/h4exceptionp . This is definitely a bug (when you run it from outside of the debugger, the system autokills the program). I forget which dashboard on Connect is the preferred one for filing these otherwise I'd do it.
More specific -
If you just put in a bunch of text, e.g. "012345678901234567890123456789012345678901234567890123456789" and start deleting from the end, it will at some point seem to decide that you want to clear all of the text and will do so. If you delete not from the end, but set the cursor just before the last "0123456789" then it will start deleting and at some point clear everything except that last "0123456789". No exceptions so far. Change it to "01234567890123456789012345678901234567890123456789 0123456789" and set the cursor to just before the last zero and start deleting and again, no problems. Change it to "012345678901234567890123456789012345678901234567890123456789.0" and delete from just before the second to last zero (i.e. same spot as previously) and no problems. But... change the text to either "01234567890123456789012345678901234567890123456789 0123456789.0" or "01234567890123456789012345678901234567890123456789 0123456789. 0", set the cursor to just after the space (and before the 0) of the "0123456789.{'0',' 0'}" block of text and it will throw an exception every time. Any text long enough to trigger the autodelete that has a period after where you are deleting from and where you set the cursor to immediately after a space will trigger this bizarro exception. Setting the cursor to before the space (which is what WP7 does by default, you have to tap to set the cursor to after the space) does not trigger the exception but handles the deletion just fine. It's literally a matter of placing the cursor exactly after the space and having a period or a comma after the cursor (possibly other punctuation marks - I only tested a period and a comma).
The HResult is -2146233088
The repro case is like above - put in enough text that deleting will trigger the auto-delete, have a space that you set the cursor after, make sure there's a period, comma, or possibly some other punctuation mark after the cursor, and start deleting. As soon as the auto-delete triggers the exception is thrown.
There's no InnerException set in the ApplicationUnhandledExceptionEventArgs, no message written to the output window indicating what it might be, and it's thrown from internal methods such that there's not even a disassembly available to see what it is or why it's happening. I did a screen cap of it, available here: http://yfrog.com/h4exceptionp . This is definitely a bug (when you run it from outside of the debugger, the system autokills the program). I forget which dashboard on Connect is the preferred one for filing these otherwise I'd do it.
More specific -
If you just put in a bunch of text, e.g. "012345678901234567890123456789012345678901234567890123456789" and start deleting from the end, it will at some point seem to decide that you want to clear all of the text and will do so. If you delete not from the end, but set the cursor just before the last "0123456789" then it will start deleting and at some point clear everything except that last "0123456789". No exceptions so far. Change it to "01234567890123456789012345678901234567890123456789 0123456789" and set the cursor to just before the last zero and start deleting and again, no problems. Change it to "012345678901234567890123456789012345678901234567890123456789.0" and delete from just before the second to last zero (i.e. same spot as previously) and no problems. But... change the text to either "01234567890123456789012345678901234567890123456789 0123456789.0" or "01234567890123456789012345678901234567890123456789 0123456789. 0", set the cursor to just after the space (and before the 0) of the "0123456789.{'0',' 0'}" block of text and it will throw an exception every time. Any text long enough to trigger the autodelete that has a period after where you are deleting from and where you set the cursor to immediately after a space will trigger this bizarro exception. Setting the cursor to before the space (which is what WP7 does by default, you have to tap to set the cursor to after the space) does not trigger the exception but handles the deletion just fine. It's literally a matter of placing the cursor exactly after the space and having a period or a comma after the cursor (possibly other punctuation marks - I only tested a period and a comma).
The HResult is -2146233088
The repro case is like above - put in enough text that deleting will trigger the auto-delete, have a space that you set the cursor after, make sure there's a period, comma, or possibly some other punctuation mark after the cursor, and start deleting. As soon as the auto-delete triggers the exception is thrown.