Well I haven't seen anything in the forums about it, but since avast 5.0 isn't that long in the tooth, I don't know how popular spysweeper is to see it being on systems with avast 5.0 and win7.
There has recently been an issue with MBAM paid version which runs resident and both avast/Alwil and MBAM have consulted and there is already a fix in the version you are using. MBAM also had/has a similar issue with MSE.
However, avast has generally worked well with other anti-spyware applications. I have SAS Pro running resident and no issues.