It is quite common to observe "repeated characters" in Skytap Linux VMs (mostly Ubuntu) via the SRA browser client.
Example symptom: A single key-stroke, such as "r", will "rrrrreplicate" like this.
Cause: It's a combination of a delay between a VM receiving a key-press and subsequent key-release event from the user's browser, and the Key Repeat setting of the VM in question.
Solution: This issue can be prevented by disabling the Key Repeat setting in the VM guest OS. For example, if you are using Ubuntu with the default Gnome desktop environment, you can disable Key Repeat within the system preferences, in the Universal Access group of settings.
For other Linux distributions, the location and availability of this setting may vary, but is typically located in the accessibility settings or keyboard settings. This will prevent keys from repeating during any delays between a key-press and a key-release event.