When controlling a host computer, you can only type 0 - 9.
You may have the security program GuardedID® installed on your computer.
Here is a comment from GuardedID tech support:
Certain programs may use Windows Message Hooks in a non-standard way that makes them appear to GuardedID® as keyloggers. Every time you type into one of these programs you will see numbers in sequence (1-2-3-4-etc.) instead of what you are typing.
Temporarily disable Anti-Keylogging.
Open Constant Guard and click Options > Configure my "Anti-keylogging" protection and temporarily disable the Anti-Keylogging feature.
Note: LogMeIn support cannot offer further assistance with GuardedID. Please visit http://www.guardedid.com/support.aspx for more information.