what is the famous bug? sorry i'm new to bitcoin mining!
Also what do people think my chances of profit are? I managed to get a 335MH/s and a 2.6GH/s ASIC for £160 from ebay and i'm currently sitting at around 3GH/s, some days the BTC build faster than others but it seems like I will be getting maybe 0.005 every couple of days... best to sell my ASICS on ebay while they are still mad money?
That's then you lose all or a large part of your Shares during a round for no apparent reason (bug, at least hope it's just a bug).
Since Slush is nowhere to be seen and things seem to run a bit unsmooth lately (don't want to say "falling apart"), let's hope nothing worse happened to the Pool.
Concerning your question about your devices, considering the current price frenzy and the almost-impossible profitability over the next months (due to skyrocketing difficulty).... Technically yes, selling them into the frenzy on EBay right now is probably your only way to actually profit. Demand is hughe and supply is minimal (at least here in Europe) - that's how it looks right now and a perfect chance to take significant profits in cold blood.
Since your USB ASICs use not much power, however, another price rise in BTC might
change that calculation (but this is entirely speculative and IMHO only valid for fast USB devices, not those old Erupters).
If you're like me and just want to mine ~1 BTC to see what happens with it in the future - you might as well take your chances and keep them until their BTC output is below a "comfort level" that you set for yourself.
Another strategy that (at least right now) seems to work is to sell older/"profitability-obsolete" devices on EBay into the frenzy and buy more modern devices straight from the manufacturer.
(I'm looking into those ~5GH/s Bi*Fury USB devices right now, for me small-profile miner those are more than sufficient)
If you're only into aquiring BTC, more experienced guys will advise to wait for a price drop and simply buy BTC. If you manage to actually buy low/sell high, that's definitely the most easy and profitable way (if you're into profit alone).
For a good calculation, I use this nifty calculator