sansa e260 - Undefined Instruction?

[ThegReg]

Hi
I've got a Sansa e260 and just installed rockbox on it
and till now everything worked fine... but than I put some more music on it and the database had to be rebuilt (sry for my bad english ^^)  but now the player just shows the failure:

Undefined Instruction
at 40009C48

I cant turn it off or do anything else...
so please could one of you help me?  

[Vortex]

Press and hold the Power/Menu button for 15-20 seconds until the player shuts off.

Then restart the player and try rebuilding the database.