Problems logging in on an iPad
If cookies are not enabled on your iPad you will not be able to login to Purple Mash, instead you will be continually taken back to the login screen.
Enabling cookies on an iPad
Locate the settings button on your iPad.
Scroll down to Safari - click it.
Choose "Block Cookies"
Make sure either "Always Allow" or "Allow from Websites I Visit" are selected.
Apply and go back to the Purple Mash login screen - you should be able to get in now.