Macbook Air freezes after standby and boots with Questionmark-folder

Hello Apple Community,

My Macbook Air 2011

i5

4gb ram

128ssd

Lion

started acting up recently. After waking it from sleep (on any of the 3 hibernate modes) it freezes(beachball, no reaction) as soon as I use an application.

Adding to that, everytime I boot it needs around 4-6 attempts to boot and not show the questionmark folder.

I did reset NVRAM and SMC, which brought very short relief, but after 2 or 3 boot sequenzes it stopped working again. I then repaired the disk in recovery mode which seemed to fix the boot problem. However, the sleep problem still persisted. I changed the hibernate setting from 2 to 1, because I assumed a harddrive problem. After that though, the mac did not wake at all after sleep and I had to force a restart. After that, the questionmark folder was back...

Does anyone have any input? I really dont know what to do, it seems both RAM and harddrive broke.However, when it boots properly it runs like always, no problems, what so ever.