I've bought top loader laundry powder AGAIN. I have a front loader and have had one for 4 years!!! Why do I keep doing this???

I really like this new powder I bought yesterday (well it smells great and was a bargain at 50% off!) so my question is, how bad is it to use it in a front loader? Will my machine spin out of control, lose it's door and spew laundry detergent all over the floor? Do I need to give my mum yet another box and get the 'right' one for my darling (fussy!) machine?

TIA!