Just a few days ago PlayStation released it’s latest firmware 3.57 for the PSVita and PlayStation TV, at the time we didn’t know for sure if it patched the whitelist hack for the PSTV. When they released firmware 3.55 they did not patch the whitelist hack either but you must have done this hack back in firmware 3.52 before updating for it to work.
Now I figure the whitelist hack was still working because custom themes were still working in firmware 3.57 but we had to make sure and thanks to @aTReYu187 for testing this we know for sure that it still works. If you want to update (which I don’t recommend) make sure you backup the whole PlayStation TV without the memory card in it and just to be safe make a backup with the memory card in it.
It’s best to play it safe and have more than one backup with and without the memory card. Also, make sure that the whitelist hack is still working after you made your backups (It’s better to be safe than sorry..) and I would also make sure the backups work with the whitelist hack still intact before doing any updating just to be safe. Next make sure you never update the live area or the whitelist hack will be gone and you will be stuck with the original whitelist for the PlayStation TV, but if you made backups you’ll be ok just re-install them via cma or qcma. I’ll say it once again if you plan on updating your PlayStation TV with the whitelist hack make sure you back it up with and without the memory card in it. It’s always best to play it safe.