That looks very similar to the error message i once got when i was experimenting with dynamically changing the link/path to a script file for a button in a post load script.
Can you replace the script with something simple like the following and make sure it runs each time?
oScript.DebugPrint "Test"
Have you tried resetting the panel?
Have you tried rebuilding customized panels?
Have you verified there isn't another custom button on another panel in the library that shares the same name, i.e. BT_Link_1? I have seen sporadic problems when this occurs, best thing i found to do was to add another button forcing the sequence to increase, i.e. BT_Link_2, apply the script to it, then delete the old button.
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David Speck II
Tennessee Software Solutions
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