I recently started a new character in Skyrim on the PS3, an argonian.
I decided to be lazy and level up my Sneak skill by rubber-banding my joysticks together and running in circle by the bear in the tutorial dungeon.
After a couple hours of watching TV, I switched back over to the game to check my progress, and I had gained 43 levels in Sneak ammounting to a total of 9 level ups for my character. I now have a level 10 character with what appears to be 40% progress towards level 11 but with only 45 skill levels gained.

My currents stats are: (forgive me, I don't know how to format spoilers)

Character Level - 10

Smithing - 15
Heavy Armor - 15
Block - 15
Two-Hand - 15
One-Hand - 22 (+2)
Archery - 15
Light Armor - 20
Sneak - 63 (+43)
Lockpick - 25
Pickpocket - 20
Speechcraft - 15
Alchemy - 15
Illusion - 15
Conjuration - 15
Destruction - 15
Restoration - 15
Restoration - 20
Alteration - 20
Enchanting - 15

To my knowledge, I should be gaining a level every 10 Skill levels, right? Yet, I've gained entirely twice as many levels as I should with relevant perk points.
I don't personally take issue with this, since I think it would be fun to have a level 160 character, but it does seem like it will make the game much harder, and I'm worried that the save file might corrupt and cause issues with my mate's PS3.

Has anyone experienced this issue, and is this something I should be concerned about?

Further (possibly) relevant information:

The PS3 in question is an old Fat that has never been flashed or tampered with, but has been reformatted twice (not that this should cause any issue I know of).
The game has been updated to the most recent patch (whenever that was...) and the PS3 to the second to most recent patch.
My mate has a subscription to PS+ and so all of the game saves are stored both on the system and backed up to online storage.
We regularly have connection issues with PSN, whether it be DNS or DNLA errors, though I'm told these are fairly common.

I created the character today around 4:30 am CST, loaded from a 'Prisoner' save made after the most recent patch.

Actually, to me, that seems about right. Levelling up takes more skill gains the higher you go...this seems pretty much like the experience I have whenever I try the sneaky-bear trick (didn't on my first character; I did it on most other characters) at the beginning of the game. It takes an absurd amount of time (OK, less than actually working for it...) and that's usually where I end up.