There is more to the Shareaholic code. but you were first asking why your page would "stall" during load.
You are using Sharaholic on two places within your forums:
1) Stock Code
Your Shareaholic ID @
Control Panel / General / Primary: Topic & Post Page Settings | Shareaholic "Setup Code"
Shareaholic "Setup Code" @
Control Panel / General / HTML Includes: Shareaholic "Setup Code"
2) Your custom code that is not part of stock UBB.threads. This is stuff you created on your own.
Your custom use of the Sharaholic code within the Custom Island was what was causing the stall in page loading.