To reproduce:
1 place a block with a button on top
2 place a repeater facing out that block
3 place on the other side of that repeater a sticky piston in the ground with a block on top
4 face another repeater out that block
5 place a block with a redstonetorch on top
6 torch doesnt deactivate

(This is not a bug in the texturepack)

Tested on both SMP and SSP