When more then 12 'replaces' are used and we do a 'QB.Web.Application.refreshSql()', the query apparently keeps trying to validate and won't allow any other webpage to be used until a browser restart. Also an IIS restart seemed to be needed after a few tries.
This was tested with the ASP.net edition versions 1.0.1 and 1.0.7.

The query looks as follows:

Select Top 1000000 tblAssets.AssetID,

replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(tblAssets.Scanserver,'sh-admin','Structure'),'smagent01','Strazzeri'),'trcoagent','Ryding'),'agent-south','SSAG'),'mgt-agent','Baywood'),'vm-agent','Valle'),'aiaagent1','AIA'),'super','Superbrush'),'gdcfile1','Harborview'),'lqaagent1','LQA'),'cwagent2','Cliffwater'),'pqafile1','PBQA'),'archagent','Archstone'),'omagent1','Omelet'),'ktnsbs1','KTN'),'vmagent1','Voyager'),'fbg-agent','Firstbev'),'wiadmin1','Water'),'bca-agent','Block'),'mag-qbserv','Magellan'),'act-rees','ACT'),'ibewagent','IBEW'),'taddscoagent','Taddsco') as Client,

  tblAssets.AssetName,

  tsysOS.OSname,

  tblAssetCustom.Warrantydate,

  tblAssetCustom.PurchaseDate

From tblAssets

  Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID

  Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype

  Inner Join tsysOS On tblAssets.OScode = tsysOS.OScode

Where tsysOS.OSname = 'Win XP'

Order By tblAssets.Scanserver,